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ALGEBRA, 


WITH 


ARITHMETIC  AND  MENSURATION, 


FROM    THE 


SANSCRIT. 


London :  PriotcJ  by  C  Ronorth, 
Bell-yard,  Temple-bar. 


ALGEBRA, 


WITH 


ARITHMETIC    AND    MENSURATION, 


FROM    THE 


SANSCRIT 


or 


BRAHMEGUPTA  AND  BHASCARA. 

• 


TRANSLATED  BY 


HENRY  THOMAS  COLEBROOKE,  Esq. 

F.  R.  S. ;  M.  JJNN.  AND  C£OL.  SOC.  AND  R.  INST.  LONDON;  AS.  SOC.  BENGAL; 

AC.  SC.  MUNICH, 


LONDON: 

JOHN  MURRAY,  ALBEMARLE  STREET. 

1817. 


.675. 


CONTENTS. 


Page. 
DiSSERTATIOJf • i 

NOTES  AND  ILLUSTRATIONS. 

A.  Scholiasts  of  Bha'scara xxv 

B.  Astronomy  of  Brahmegupta    .     ■. xxviii 

C.  Brahma-sidd'hdnta,  Title  of  his  Astronomy xxx 

D.  Verification  of  his  Text xxxi 

E.  Chronology  of  Astronomical  Authorities,  according  to  Astrono- 

mers of  Ujjayani xxxiii 

F.  Age  of  Brahmegupta,  from  astronomical  data xxxv 

G.  Aryabhatta's  Doctrine xxxvii 

H.  (Reference  from  p.  ix.  1.21.)     Scautlness  of  Additions  by  later 

Writers  on  Aljgfpbra xl 

I.      Age  of  AnrABHATTA xU 

K.  Writings  and  Age  of  Vara'ha-mihira xlv 

L.  Introduction  and  Progress  of  Algebra  among  the  Italians    ...  li 

M.  Arithmetics  of  Diophantus Ixi 

N.  Progress  and  Proficiency  of  the  Arabians  in  Algebra Ixiv 

O.  Communication  of  the  Hindus  with  Western  Nations  on  Astro- 
logy and  Astronomy Ixxviii 

BHASCARA. 

ARITHMETIC  (Lildvatl) 

Chapter  I.     Introduction.     Axioms.     Weights  and  Measures     .     .  1 

Chapter  II.     Sect.  I.       Invocation.     Numeration 4 

Sect.  II.     Eight  Operations  of  Arithmetic :  Addition,  &c.  5 

Sect.  III.  Fractions 13 

Sect.  IV.    Cipher 19 


I 


Chapter 


Chapter 


Chapter 


Chapter 
Chapter 
Chapter 
Chapter 
Chapter 
Chapter 
Chapter 
Chapter 


CONTENTS. 

III.  Afiscellaneous. 

Sect.  I.       Inversion 21 

Sect.  II.     Supposition 23 

Sect.  III.  Concurrence  .     ; 26 

Sect.  IV.    Problem  concerning  Squares      ...  27 

Sect.  V.      Assimilation 29 

Sect.  VI.    Rule  of  Proportion 33 

IV.  Mixture. 

Sect.  I.      Interest 39 

Sect.  II.     Fractions 42 

Sect.  III.  Purchase  and  Sale 43 

Sect.  IV.    A  Problem 45 

Sect.  V.      Alligation 46 

Sect.  VI.    Permutation  and  Combination  ...  49 

V.  Progression. 

Sect.  I.      Arithmetical 51 

Sect.  II.     Geometrical 55 

VI.  Plane  FSgure        58 

VII.  Excavations  and  Content  of  Solids 97 

VIII.  Stacks 100 

IX.  Saw 101 

X.  Mound  of  Grain i03 

XI.  Shadow  of  a  Gnomon 106 

XII.  Pulverizer  fCM^/aca) 112 

XIII.  Combination 123 


ALGEBRA  (Vija-gatiita.) 

Chapter  I.     Sect.  I.     Invocation,  &c 129 

Sect.  II.    Algorithm  of  Negative  and  Affirmative 

Quantities       133 

Sect.  III.  of  Cipher 136 

Sect.  IV. of  Unknown  Quantity  .     .  ]  39 

Sect.  V. of  Surds 145 

Chapter  II.         Pulverizer 156 


CONTENTS. 

Chapter  III.        Affected  Square.     Sect.  I. 170 

Sect.  II.     Cyclic  Method '.     .  175 

Sect.  III.  Miscellaneous 179 

Chapter  IV.         Simple  liquation 185 

Chapter  V.          Quadratic,  &c.  Equations 207 

Chapter  VI.         Multiliteral  Equations 227 

Chapter  VII.       Varieties  of  Quadratics 245 

Chapter  VIII.     Equation  involving  a  Factum  of  Unknown  Quantities  268 

Chapter  IX.         Conclusion 275 

BRAHMEGUPTA. 

CHAPTER  XII.     ARITHMETIC  (Gariita.) 

Sect.  I.         Algorithm 277 

Sect.  II.       Mixture 287 

Sect.  III.     Progression 29() 

Sect.  IV.      Plane  Figure 305 

Sect.  V.        Excavations 312 

Sect.  VI.      Stacks 314 

Sect.  VII.    Saw 315 

&c^  F7//.  Mounds  of  Grain 316 

Sect.  IX.     Measure  by  Shadow 317 

Sect.  X.       Supplement 319 

CHAPTER  XVIII.    ALGEBRA  (CuHaca.) 

Sect.  I.         Pulverizer 325 

Sect.  II.       Algorithm 339 

Sect.  III.     Simple  Equation 344 

Sect.  IV.      Quadratic  Equation 346 

Sect.  V.        Equation  of  several  unknown    .     .     .  348 

Sect.  VI.      Equation  involving  a  factum     ...  361 

Sect.  VII.    Square  affected  by  coefficient     .     .     .  363 

Sect.  VIII.  Problems 373 


DISSERTATION. 


The  history  of  sciences,  if  it  want  the  prepossessing  attractions  of  political 
histoiy  and  narration  of  events,  is  nevertheless  not  wholly  devoid  of  in- 
terest and  instruction.  A  laudable  curiosity  prompts  to  inquire  the  sources 
of  knowledge ;  and  a  review  of  its  progress  furnishes  suggestions  tending  to 
promote  the  same  or  some  kindred  study.  We  would  know  the  people  and 
the  names  at  least  of  the  individuals,  to  whom  we  owe  particular  discoveries 
and  successive  steps  in  the  advancement  of  knowledge.  If  no  more  be 
obtained  by  the  research,  still  the  inquiry  has  not  been  wasted,  which  points 
aright  the  gratitude  of  mankind. 

In  the  history  of  mathcuiatical  science,  it  has  long  been  a  question  to 
whom  the  invention  of  Algebraic  analysis  is  due?  among  what  people,  in 
what  region,  was  it  devised  ?  by  whom  was  it  cultivated  and  promoted  ?  or 
by  whose  labours  was  it  reduced  to  form  and  system?  and  finally  from  what 
quarter  did  the  diffusion  of  its  knowledge  proceed  ?  No  doubt  indeed  is 
entertained  of  the  source  from  which  it  was  received  immediately  by  modern 
Europe ;  though  the  channel  have  been  a  matter  of  question.  We  are  well 
assured,  that  the  Arabs  were  mediately  or  immediately  our  instructors  in  this 
study.  But  the  Arabs  themselves  scarcely  pretend  to  the  discovery  of 
Algebra.  They  were  not  in  general  inventors  but  scholars,  during  the 
short  period  of  their  successful  culture  of  the  sciences  :  and  the  germ  at  least 
of  the  Algebraic  analysis  is  to  be  found  among  the  Greeks  in  an  age  not 
precisely  determined,  but  more  than  probably  anterior  to  the  earliest  dawn 
of  civilization  among  the  Arabs:  and  this  science  in  a  more  advanced  state 
subsisted  among  the  Hindus  prior  to  the  earliest  disclosure  of  it  by  the 
Arabians  to  modern  Europe. 

The  object  of  the  present  publication  is  to  exhibit  the  science  in  the  state 
in  which  the  Hindus  possessed  it,  by  an  exact  version  of  the  most  approved 

b 


ii  DISSERTATION. 

treatise  on  it  in  the  ancient  language  of  India,  with  one  of  the  earlier  treatises 
(the  only  extant  one)  from  which  it  was  compiled.  The  design  of  this  pre- 
liminary dissertation  is  to  deduce  from  these  and  from  the  evidence  which 
will  be  here  offered,  the  degree  of  advancement  to  which  the  science  had 
arrived  in  a  remote  age.  Observations  will  be  added,  tending  to  a  compa- 
rison of  the  Indian,  with  the  Arabian,  the  Grecian,  and  the  modern  Algebra: 
and  the  subject  will  be  left  to  the  consideration  of  the  learned,  for  a  con- 
clusion to  be  drawn  by  them  from  the  internal,  no  less  than  the  external 
proof,  on  the  question  who  can  best  vindicate  a  claim  to  the  merit  of  having 
originally  invented  or  first  improved  the  methods  of  computation  and  analysis, 
which  are  the  groundwork  of  both  the  simple  and  abstruser  parts  of  Mathe- 
matics ;  that  is,  Arithmetic  and  Algebra :  so  far  at  least  as  the  ancient  inven- 
tions are  affected;  and  also  in  particular  points,  where  recent  discoveries  are 
concerned. 

In  the  actual  advanced  condition  of  the  analytic  art,  it  is  not  hoped,  that 
this  version  of  ancient  Sanscrit  treatises  on  Algebra,  Arithmetic,  and  Mensu- 
ration, will  add  to  the  resources  of  the  art,  and  throw  new  light  on  mathe- 
matical science,  in  any  othnr  respect,  than  as  concerns  its  history.  Yet  the 
remark  may  not  seem  inapposite,  that  had  an  earlier  version  of  these  treatises 
been  completed,  had  they  been  translated  and  given  to  ilie  public,  when  the 
notice  of  mathematicians  was  first  drawn  to  the  attainments  of  the  Hindus 
in  astronomy  and  in  sciences  connected  with  it,  sonie  addition  would  have 
been  then  made  to  the  means  and  resources  of  Algebra  for  the  general  solu- 
tion of  problems  by  methods  which  have  been  re-invented,  or  have  been  per- 
fected, in  the  last  age. 

The  treatises  in  question,  which  occupy  the  present  volume,  are  the  Vjja- 
ganita  and  Lilcwati  of  Bhascara  a'cha'rya  and  the  Gaiiitad'haya  and 
Cuiiacdd'hyaya  of  Brahmegupta.  Tlie  two  first  mentioned  constitute  the 
preliminary  portioiiof  Bhascara's  Course  of  Astronomy,  entitled  Sidd'hanta- 
sirdmani.  Tlie  two  last  are  the  twelfth  and  eighteenth  chapters  of  a  similar 
course  of  astronomy,  by  Brahmegupta,  entitled  Brahna-siddlidnta. 

The  questions  to  be  first  examined  in  relation  to  these  works  are  their 
authenticity  and  their  age.  To  the  consideration  of  those  points  we  now 
proceed. 

The  period  when  Bha'scara,  the  latest  of  the  authors  now  named,  flou- 
rished, and  the  time  when  he  wrote,  are  ascertained  with  unusual  precision. 


DISSERTATION. 


m 


He  completed  his  great  work,  the  Sldd'hanta-siromarii,  as  he  himself  informs 
us  in  a  passage  of  it,'  in  the  year  1072  Saca.  This  information  receives  cor- 
roboration, if  any  be  wanted,  from  the  date  of  another  of  his  works,  the 
Caj-ana-cutuhala,  a  practical  astronomical  treatise,  the  epoch  of  which  is 
1105  Saca;''  33  years  subsequent  to  the  completion  of  the  systematic 
treatise.  The  date  of  the  Sidd' hanta-siromaiii,  of  which  the  Vija-ganita  and 
Lilavati  are  parts,  is  fixt  then  with  the  utmost  exactness,  on  the  most  satis- 
factory grounds,  at  the  middle  of  the  twelfth  century  of  the  Christian  era, 
A.D.  1150.' 

The  genuineness  of  the  text  is  established  with  no  less  certainty  by  nume- 
rous commentaries  in  Sanscrit,  besides  a  Persian  version  of  it.  Those  com- 
mentaries comprise  a  perpetual  gloss,  in  which  every  passage  of  the  original 
is  noticed  and  interpreted  :  and  every  word  of  it  is  repeated  and  explained. 
A  comparison  of  them  authenticates  the  text  where  they  agree ;  and  would 
serve,  where  they  did  not,  to  detect  any  alterations  of  it  that  might  have 
taken  place,  or  variations,  if  any  had  crept  in,  subsequent  to  the  composition 
of  the  earliest  of  them.  A  careful  collation  of  several  commentaries,*  and 
of  thi'ee  copies  of  the  original  work,  has  bppn  made  ,  and  it  will  be  seen  ia 
the  notes  to  the  translation  hn»  unimportant  are  the  discrepancies. 

From  comparison  and  collation,  it  appears  then,  that  the  work  of  Bha's- 
CARA,  exhibiting  the  same  uniform  text,  which  the  modem  transcripts  of  it 
do,  was  in  the  hands  of  both  Mahommedans  and  Hindus  between  two  and 
three  centuries  ago :  and,  numerous  copies  of  it  having  been  diffused  through- 
out India,  at  an  earlier  period,  as  of  a  performance  held  in  high  estimation, 
it  was  the  subject  of  study  and  habitual  reference  in  countries  and  places 
so  remote  from  each  other  as  the  north  and  west  of  India  and  the  southern 
peninsula :  or,  to  speak  with  the  utmost  precision,  Jambusara  in  the  west, 
Agra  in  North  Hindustan,  and  Parthapiwa,  Golagrdma,  Amar6>vat't,  and 
Nandigrcima,  iu  the  south. 

*  GolMhydya ;  or  l«x:ture  on  the  sphere,    c.  11.  §  SG,     As.  Res.  vol.  12.  p.  314. 

•  As.  Res.  ibid. 

'  Though  the  matter  be  introductory,  the  preliminary  treatises  on  arithmetic  and  algebra  may 
have  been  added  subsequently,  as  is  hinted  by  one  of  the  commentators  of  the  astronomical  part. 
(Vdrtic.)  The  order  there  intimated  places  them  after  the  computation  of  planets,  but  before  the 
treatise  on  ipherics;  which  cotstains  the  date. 

♦  Note  A. 

b2 


iv  DISSERTATION. 

This,  though  not  marking  any  extraordinary  antiquity,  nor  approaching 
to  that  of  the  author  himself,  was  a  material  point  to  be  determined  :  as  there 
will  be  in  the  sequel  occasion  to  show,  that  modes  of  analysis,  and,  in  parti- 
cular, general  methods  for  the  solution  of  indeterminate  problems  both  of  the 
first  and  second  degrees,  are  taught  in  the  Vjja-ganita,  and  those  for  the  first 
degree  repeated  in  the  Lildvatl,  which  were  unknown  to  the  mathematicians 
of  the  west  until  invented  anew  in  the  last  two  centuries  by  algebraists  of 
France  and  England.  It  will  be  also  shown,  that  Bhascara,  who  himself 
flourished  more  than  six  hundred  and  fifty  years  ago,  was  in  this  respect  a 
compiler,  and  took  those  methods  from  Indian  authors  as  much  more  aucient 
than  himself 

That  Bha'scaka's  text  (meaning  the  metrical  rules  and  examples,  apart 
from  the  interspersed  gloss;)  had  continued  unaltered  from  the  period  of  the 
compilation  of  his  work  until  the  age  of  the  commentaries  now  current,  is 
apparent  from  the  care  with  which  they  have  noticed  its  various  readings, 
and  the  little  actual  importance  of  these  variations;  joined  to  the  considera- 
tion, that  earlier  commentaries,  including  tlie  author's  own  explanatory 
annotations  of  his  text,  -wcro  extant,  and  lay  before  them  for  consultation 
and  reference.  Those  earlier  commentaries  ar«  occasionally  cited  by  name  : 
particularly  the  Ganita-caumudi,  which  is  repeatedly  quote^i  by  more  than 
one  of  the  scholiasts.* 

No  doubt  then  can  be  reasonably  entertained,  that  we  now  possess  the 
arithmetic  and  algebra  of  Bha'scara,  as  composed  and  published  by  him  in 
the  middle  of  the  twelfth  century  of  the  Christian  era.  The  age  of  his  pre- 
cursors cannot  be  determined  with  equal  precision.  Let  us  proceed,  how- 
ever, to  examine  the  evidence,  such  as  we  can  at  present  collect,  of  their 
antiquity. 

Towards  the  close  of  his  treatise  on  Algebra,*  Bha'scara  informs  us,  that 
it  is  compiled  and  abridged  from  the  more  diffuse  works  on  the  same  subject, 
bearing  the  names  of  Brahme,  (meaning  no  doubt  Brahmegupta,) 
Srid'hara  and  Padmana'bha;  and  in  the  body  of  his  treatise,  he  has  cited 
a  passage  of  Srid'hara's  algebra,'  and  another  of  Padmana'bha's.*  He 
repeatedly  adverts  to  preceding  writers,  and  refers  to  them  in  general  terms,, 

'  For  example,  by  Su'ryada'sa,  under  Lildvati,  §74;  and  still  more  frequently  by  Ranca- 
naYha. 

»  Vija-gaiiUa,  §  218.  '  Ibid.  §  131.  ♦  Ibid.  §  142. 


DISSERTATION.  v 

where  his  commentators  understand  him  to  allude  to  Arya-bhat't'a,  to 
Brahmegupta,  to  the  latter's  scholiast  Chaturve'da  Prit'hudaca  Swa'miV 
and  to  the  other  writers  above  mentioned. 

Most,  if  not  all,  of  the  treatises,  to  which  he  thus  alludes,  must  have  been 
extant,  and  in  the  hands  of  his  commentators,  when  they  wrote;  as  appears 
from  their  quotations  of  them;  more  especially  those  of  Brahmegupta  and 
Arya-bhat't'a,  who  are  cited,  and  particularly  the  first  mentioned,  in  several 
instances."  A  long  and  diligent  research  in  various  parts  of  India,  has,  how- 
ever, failed  of  recovering  any  part  of  the  Padmanabha  v'lja,  (or  Algebra  of 
Padmana'bha,)  and  of  the  Algebraic  and  other  works  of  Arya-bh  atta.'  But 
the  translator  has  been  more  fortunate  in  regard  to  the  works  of  Suii)'HARA 
and  Brahmegupta,  having  in  his  collection  Srid'hara's  compendium  of 
arithmetic,  and  a  copy,  incomplete  however,  of  tlie  text  and  scholia  of  Brah- 
megupta's  Brahma-sidd'hanta,  comprising  among  other  no  less  interesting 
matter,  a  chapter  treating  of  arithmetic  and  mensuration  ;  and  another,  the 
subject  of  which  is  algebra :  both  of  them  fortunately  complete.* 

The  commentary  is  a  perpetual  one ;  successively  quoting  at  length  each 
A'erse  of  the  text ;  proceeding  to  the  interpretation  of  it,  word  by  word  ;  and 
subjoining  elucidations  and  remarks  :  and  its  colophon,  at  the  close  of  each 
chapter,  gives  the  title  of  the  work  and  name  of  the  author.'  Now  the  name, 
which  is  there  given,  Chaturve'da  Prit'hudaca  Swa'mi,  is  that  of  a  cele- 
brated scholiast  of  Brahmegupta,  frequently  cited  as  such  by  the  commen- 
tators of  Bha'scara  and  by  other  astronomical  writers:  and  the  title  of  the 
work,  Brahma-siddhunta,  or  sometimes  Brahma  sphuta-sidd' hdnta,  corre- 
sponds, in  the  shorter  form,  to  the  known  title  of  Brahmegupta's  treatise  in 
the  usual  references  to  it  by  Bha'scara's  commentators;*  and  answers,  in  the 
longer  form,  to  the  designation  of  it,  as  indicated  in  an  introductory  couplet 
which  is  quoted  from  Brahmegupta  by  Lacshmida'sa,  a  scholiast  of 
Bha'scara.^ 

Remarking  this  coincidence,  the  translator  proceeded  to  collate,  with  the 


'  ^V'-g"'*-  Ch.  5.  note  of  Su'rtada'sa.     Also  V'tj.'gaii.  §  174  ;  and  Lil.  §  246  ad  finem. 

*  For  example,  under  Z,)/.  Ch.  11.  '   Note  G.  ♦  Note  B. 

'  Vitand-bhdshya  by  Chatuuve'da  Piut'uu'daca  Swa'mi,   son  of  Mad'uu'su'dana,  on  tlie 
Brahma-sidiThdnta  ;  (or  sometimes  Brahma-sphuta-sidd'/tunta.) 

*  They  often  quote  from  the  Drahma-sidd'hunta  after  premising  a  reference  to  Brahmegupta. 
-'  NoteC. 


vi  DISSERTATION. 

text  and  commeatury,  numerous  quotations  from  both,  which  he  found  in 
Bha'scara's  writings  or  in  those  of  his  cxpositoi-s.  The  result  confirmed  the 
indication,  and  established  the  identity  of  both  text  and  scholia  as  Buahme- 
gupta's  treatise,  and  the  gloss  of  Prit'hu'daca.  The  authenticity  of  this 
Brakma-sidd'hdttta  is  further  confirmed  by  numerous  quotations  in  the  com- 
mentary of  Bhatt6tpala  on  the  sanhitA  of  Vara'ha  mihira  :  as  the  quo- 
tations from  the  Brahma-sidd'hunta  in  that  commentaiy,  (which  is  the  M'ork 
of  an  author  who  flourished  eight  hundred  and  fifty  years  ago,)  are  verified 
in  the  copy  under  consideration.  A  few  instances  of  both  will  suffice  ;  and 
cannot  fail  to  produce  conviction.' 

It  is  confidently  concluded,  that  the  Chapters  on  Arithmetic  and  Algebra, 
fortunately  entire  in  a  copy,  in  many  parts  imperfect,  of  Brahmegupta's 
celebrated  work,  as  here  described,  are  genuine  and  authentic.  It  remains 
to  investigate  the  age  of  the  author. 

Mr.  Davis,  who  first  opened  to  the  public  a  correct  view  of  the  astronomical 
computations  of  the  Hindus,*  is  of  opinion,  that  Brahmegupta  lived  in  the 
7th  century  of  the  Christian  era.'  Dr.  William  Hunter,  who  resided  for 
some  time  with  a  British  Embassy  at  l/jjai/ani,  and  made  diligent  researches 
into  the  remains  of  Indian  science,  at  that  ancient  seat  of  Hindu  astronomical 
knowledge,  was  there  furnished  by  the  learned  astronomers  whom  he  consulted, 
with  the  ages  of  the  principal  ancient  authorities.  They  assigned  to  Brahme- 
gupta the  date  of  550  Saca  ;  which  answers  to  A.  D.  628.  The  grounds, 
on  which  they  proceeded,  are  unfortunately  not  specified  :  but,  as  they  gave 
Bk  a'scara's  age  correctly,  as  well  as  several  other  dates  right,  which  admit  of 
being  verified ;  it  is  presumed,  that  they  had  grounds,  though  unexplained,  for 
the  information  which  they  communicated.* 

Mr.  Bentley,  who  is  little  disposed  to  favour  the  antiquity  of  an  Indian 
astronomer,  has  given  his  reasons  for  considering  the  astronomical  system 
which  Brahmegupta  teaches,  to  be  between  twelve  and  thirteen  hundred 
years  old  (12631  years  in  A.  D.  1799)-'  Now,  as  the  system  taught  by  this 
author  is  professedly  one  corrected  and  adapted  by  him  to  conform  with  the 
observed  positions  of  the  celestial  objects  when  he  wrote,*  the  age,  when 
their  positions  would  be  conformable  with  the  results  of  computations  made 
as  by  him  directed,  is  precisely  die  age  of  the  author  himself :  and  so  far  as 

»  Note  D.  *  As.  Res.  2.  225.  »  Ibid.  9-  242. 

♦  Note  E.  »  As.  Res.  6.  586.  •  Supra. 


DISSERTATION.  iVii 

Mr.  Bentley's  calculations  may  be  considered  to  approximate  to  the  truth, 
the  date  of  Brahmegupta's  performance  is  determined  with  hke  approach 
to  exactness,  within  a  certain  latitude  however  of  uncertainty  for  allowance 
to  be  made  on  account  of  the  inaccuracy  of  Hindu  observations. 

The  translator  has  assigned  on  former  occasions*  the  grounds  upon  which 
he  sees  reason  to  place  the  author's  age,  soon  after  the  period,  when  the  ver- 
nal  equinox  coincided  with  the  beginning  of  the  lunar  mansion  and  zodiacal 
asterism  Aswini,  where  the  Hindu  ecliptic  now  commences.  He  is  sup- 
ported in  it  by  the  sentiments  of  Bha'scara  and  other  Indian  astronomers, 
who  infer  from  Brahmegupta's  doctrine  concerning  the  solstitial  points,  of 
which  he  does  not  admit  a  periodical  motion,  that  he  lived  when  the  equi- 
noxes did  not,  sensibly  to  him,  deviate  from  the  beginning  of  Aswini  and 
middle  of  Chiird  on  the  Hindu  sphere.*  On  these  grounds  it  is  maintained, 
that  Brahmegupta  is  rightly  placed  in  the  sixth  or  beginning  of  the  seventh 
century  of  the  Christian  era  ;  as  the  subjoined  calculations  will  more  parti- 
cularly show.'  The  age  when  Brahmegupta  flourished,  seems  then,  from 
the  concurrence  of  all  these  arguments,  to  be  satisfactorily  settled  as  ante- 
cedent to  the  earliest  dawn  of  the  culture  of  sciences  among  the  Arabs  ;  and 
consequently  establishes  the  fact,  that  the  Hindus  were  in  possession  of 
algebra  before  it  was  known  to  the  Arabians. 

Brahmegupta's  treatise,  however,  is  not  the  earliest  work  known  to  have 
been  written  on  the  same  subject  by  an  Indian  author.  The  most  eminent 
scholiast  of  Bha'scara*  quotes  a  passage  of  Arya-bh att'a  specifying  algebra 
under  the  designation  of  Fija,  and  making  separate  mention  of  Cut't'aca,  which 
more  particularly  intends  a  problem  subservient  to  the  general  method  of 
resolution  of  indeterminate  problems  of  the  first  degree :  he  is  understood  by 
another  of  Bha'scara's  commentators'  to  be  at  the  head  of  the  elder  writers, 
to  whom  the  text  then  under  consideration  adverts,  as  having  designated  by 
the  name  of  Mad'hyamdharana  the  resolution  of  affected  quadratic  equations 
by  means  of  the  completion  of  the  square.  It  is  to  be  presumed,  therefore, 
that  the  treatise  of  Arya-bhatta  then  extant,  did  extend  to  quadratic  equa- 
tions in  the  determinate  analysis  ;  and  to  indeterminate  problems  of  the  first 
degree  ;  if  not  to  those  of  the  second  likewise,  as  most  probably  it  did. 

This  ancient  astronomer  and  algebraist  was  anterior  to  both  Vara'ha-mihiha 

'  A».  Res.  9.  S29.  *  Ibid.  12.  p.  215.  *  Note  F. 

♦  Ganesa,  a  distiguished  mathematician  and  astronomer.  '  Sun.  on  Fi;'.-ga».  §  128. 


▼iii       '  DISSERTATION. 

and  Brahmegupta  ;  being  repeatedly  named  by  the  latter;  and  the  determi- 
nation of  the  age  when  he  flourished  is  particulai  ly  interesting,  as  his  astro- 
nomical system,  though  on  some  points  agreeing,  essentially  disagreed  on 
others,  with  that  which  those  authors  have  followed,  and  which  the  Hindu 
astronomers  still  maintain.' 

He  is  considered  by  the  commentators  of  the  Suryasidd'hanta  and  Siroma/ii,^ 
as  the  earliest  of  uninspired  and  mere  human  writers  on  the  science  of  astro- 
nomy ;  as  having  introduced  requisite  corrections  into  the  system  of  Para'- 
SARA,  from  whom  he  took  the  numbers  for  the  planetary  mean  motions;  as 
having  been  followed  in  the  tract  of  emendation,  after  a  sufficient  interval  to 
make  further  correction  requisite,  by  Durgasinha  and  Mihira;  who  were 
again  succeeded  after  a  further  interval  by  Brahmegupta  son  of  Jishnu.' 

In  short,  Arva-bhat'ta  was  founder  of  one  of  the  sects  of  Indian  astrono- 
mers, as  Puli's'a,  an  author  likewise  anterior  to  both  Vara'hamihira  and 
Brahmegupta,  was  of  another  :  which  were  distinguished  by  names  derived 
from  the  discriminative  tenets  respecting  the  commencement  of  planetary 
motions  at  sun-rise  according  to  the  first,  but  at  midnight  according  to  the 
latter,*  on  the  meridian  of  LancA,  at  the  bejrinninsr  of  the  arreat  astronomical 
cycle.  A  third  sect  began  the  astronomical  day,  as  well  as  the  great  period, 
at  noon. 

His  name  accompanied  the  intimation  which  the  Arab  astronomers  (under 
the  Abbasside  Khalifs,  as  it  would  appear,)  received,  that  three  distinct  astro- 
nomical systems  were  current  among  the  Hindus  of  those  days :  and  it  is  but 
slightly  corrupted,  certainly  not  at  all  disguised,  in  the  Arabic  representation 
oi'\t  A rjabahar,  or  rather  Arjabhar.^  The  two  other  systems  were,  first,  Brah- 
megupta's  Sidd'hdnta,  whicli  was  the  one  they  became  best  acquainted  with, 
and  to  which  they  apply  the  denomination  oi' the  sind-hitid;  and  second,  that 

'  Note  G.  •  Nrtsmka  on  Sur,  Gan'e's'a  pref.  to  Grah.  Ugh. 

'  As.  Res.  2.  235,  242,  and  244;  and  Note  Jl. 

f 

♦  Brahmegupta,  ch.  U.  The  names  are  Audayacahom  Udai/a  rising;  and  Ardkaratrka  from 
Ardhar&tri,  midnight.  The  third  school  is  noticed  by  Bhattotpala  the  scholiast  of  Vara'ha 
MIHIRA,  under  the  denomination  of  Mudhyandinas,  as  alleging  the  commencement  of  the  astrono- 
mical period  at  noon  :  (from  Madhyandina,  mid-day.) 

'  The  Sanscrtt  i,  it  is  to  be  remembered,  is  the  character  of  a  peculiar  sound  often  mistaken  for  r, 
and  which  the  Arabs  were  likely  so  to  write,  rather  than  with  a  te  or  with  a  tau.  The  Hindi  i  is 
generally  written  by  the  English  in  India  with  an  r.  Example  :  Ber  (rata),  the  Indian  fig. 
vulg.  Banian  tree. 


DISSERTATION.  ix 

of  j^rca  the  sun,  which  they  write  Arcand,  a  corruption  still  prevalent  in 
the  vulgar  Hiiidi} 

Aryabhatt'a  appears  to  have  had  more  correct  notions  of  the  true  explana- 
tion of  celestial  phenomena  than  Brahmf.gupta  himself;  who,  in  a  few  in- 
stances, correcting  errors  of  his  predecessor,  but  oftener  deviating  from  that 
predecessor's  juster  views,  has  been  followed  by  the  herd  of  modern  Hindu 
astronomers,  in  a  system  not  improved,  but  deteriorated,  since  the  time  of 
the  more  ancient  author. 

Considering  the  proficiencj' of  Arvabiiat'ta  in  astronomical  science,  and 
adverting  to  the  fact  of  his  having  written  upon  Algebra,  as  well  as  to  the 
circumstance  of  his  being  named  by  numerous  writers  as  the  founder  of  a 
sect,  or  author  of  a  system  in  astronomy,  and  being  quoted  at  the  head  of 
algebraists,  when  the  commentators  of  extant  treatises  have  occasion  to 
mention  early  and  original'  writers  on  this  branch  of  science,  it  is  not  neces- 
sary to  seek  further  for  a  mathematician  qualified  to  have  been  the  great  im- 
prover of  the  analytic  art,  and  likely  to  have  been  the  person,  by  whom  it 
was  carried  to  the  pitch  to  which  it  is  found  to  have  attained  among  the 
Hindus,  and  at  which  it  is  observed  to  bo  nearly  stationary  through  the  long- 
lapse  of  ages  which  have  siaice  passed:  the  later  additions  being  i'ew  and  un- 
essential in  the  writings  of  Buahmegupta,  of  Bua'scara,  and  of  Jnya'na 
RAJA,  though  they  lived  at  intervals  of  centuries  from  each  other. 

AftYABHATTA  then  being  the  earliest  author  known  to  have  treated  of 
Algebra  among  the  Plindus,  and  being  likely  to  be,  if  not  the  inventor,  tlw 
improver,  of  that  analysis,  by  whom  too  it  was  pushed  nearly  to  the  whole 
degree  of  excellence  which  it  is  found  to  have  attained  among  them;  it  be- 
comes in  an  especial  manner  interesting  to  investigate  any  discoverable  trace 
in  the  absence  of  better  and  more  direct  evidence,  which  may  tend  to  fix  the; 
date  of  his  labours,  or  to  indicate  the  time  which  elapsed  between  him  and 
Bkahmegupta,  whose  age  is  more  accurately  determined.' 

Taking  Aryabhatt'a,  for  reasons  given  in  the  notes,'  to  have  preceded 
BRAiiMEGupTAand  VARA'iiAJirniRA  by  several  centuries;  and  Brahmegupta 
to  have  flourished  about  twelve  hundred  years  ago;*  and  Vara'ha  mihira, 
concerning  whose  works  and  age  some  further  notices  will  be  found  in  a  sub- 


'  See  notes  I,  K,  and  N.  '  SuaYA-DA'sA  on  Vija-gaiiUa,  ch.  5, 

^  Note  I.  ♦  See  before  and  note  F. 


X  DISSERTATION. 

joined  note,*  to  have  livqd  at  the  beginning  of  the  sixth  century  after  Christ,* 
it  appears  probable  that  this  earhest  of  known  Hindu  algebraists  wrote  as 
far  back  as  the  fifth  century  of  the  Christian  era;  and,  perhaps,  in  an  earlier 
age.  Hence  it  is  concluded,  tliat  he  is  nearly  as  ancient  as  the  Grecian 
algebraist  Diophantus,  supposed,  on  the  authority  of  Abulfaraj,^  to  have 
flourished  in  the  time  of  the  Emperor  Julian,  or  about  A.  D.  360. 

Admitting  the  Hindu  and  Alexandrian  authors  to  be  nearly  equally 
ancient,  it  must  be  conceded  in  favour  of  the  Indian  algebraist,  that  he  was 
more  advanced  in  the  science ;  since  he  appears  to  have  been  in  possession  of 
the  resolution  of  equations  involving  several  unknown,  which  it  is  not  clear, 
nor  fairly  presumable,  that  Diophantus  knew ;  and  a  general  method  for 
indeterminate  problems  of  at  least  the  first  degree,  to  a  knowledge  of  which 
the  Grecian  algebraist  had  certainly  not  attained  ;  though  he  displays  infinite 
sagacity  and  ingenuity  in  particular  solutions ;  and  though  a  certain  routine 
is  discernible  in  them. 

A  comparison  of  the  Grecian,  Hitidu,  and  Arabian  algebras,  will  more  dis- 
tinctly show,  which  of  them  had  made  the  greatest  progress  at  the  earliest 
age  of  each,  that  can  be  now  traced. 

The  notation  or  algorithm  of  Algebra  is  so  essential  to  this  art,  as  to  deserve 
tlie  first  notice  in  a  review  of  the  Indian  method  of  analysis,  and  a  compari- 
son of  it  with  the  Grecian  and  Arabian  algebras.  The  Hindu  algebraists  use 
abbreviations  and  initials  for  sj'mbols:  they  distinguish  negative  quantities 
by  a  dot;*  but  have  not  any  mark,  besides  the  absence  of  the  negative  sign, 
to  discriminate  a  positive  quantity.  No  marks  or  symbols  indicating  opera- 
tions of  addition,  or  multiplication,  &c.  are  employed  by  them :  nor  any  an- 
nouncing equality'  or  relative  magnitude  (greater  or  less).*  But  a  factum  is 
denoted  by  the  initial  syllable  of  a  word  of  that  import,'  subjoined  to  the 
terms  which  compose  it,  between  which  a  dot  is  sometimes  interposed.  A 
fraction  is  indicated  by  placing  the  divisor  under  the  dividend,^  but  without 
a  line  of  separation.     The  two  sides  of  an  equation  are  ordered  in  the  same 


'  Note  K.  •'■  See  before  and  note  E.  '  Pocockc's  edition  and  translation,  p.  89. 

*  Fy.-gan.  §  4. 

'  The  sign  of  equality  was  first  used  by  Robert  Recorde,  because,  as  he  says,  no  two  things  can 
-be  more  equal  than  a  pair  of  parallels,  or  geniowe  lines  of  one  length.     Hutton. 

*  The  signs  of  relative  magnitude  were  first  introduced  into  European  algebra  by  Harriot. 
'  Py.-ga«.  §21.  »Li7.  §33. 


DISSERTATION.  xi 

manner,  one  under  the  other:'  and,  this  method  of  placing  terms  under  each 
other  being  likewise  practised  upon  other  occasions,"  the  intent  is  in  the 
instance  to  be  collected  from  the  recital  of  the  steps  of  the  process  in  words 
at  length,  which  always  accompanies  the  algebraic  piocess.  That  recital  is 
also  requisite  to  ascertain  the  precise  intent  of  vertical  lines  interposed 
between  the  terms  of  a  geometric  progression,  but  used  also  upon  other 
occasions  to  separate  and  discriminate  cjuantities.  The  symbols  of  unknown 
quantity  are  not  confined  to  a  single  one:  but  extend  to  ever  so  great  a 
variety  of  denominations:  and  the  characters  used  are  initial  syllables  of  the 
names  of  colours,'  excepting  the  first,  which  is  the  initial  o^ydvat-tavat,  as  much 
as;  words  of  the  same  import  with  Bombelli's  tanto;  used  by  him  for  thesame 
purpose.  Colour  therefore  means  unknown  quantity,  or  the  symbol  of  it: 
and  the  same  Sanscrit  word,  tarna,  also  signifying  a  literal  character,  letters 
are  accordingly  employed  likewise  as  symbols;  either  taken  from  the  alpha- 
bet ;*  or  else  initial  syllables  of  words  signifying  the  subjects  of  the  problem  ; 
whether  of  a  general  nature,'  or  specially  the  names  of  geometric  lines  in 
algebraic  demonstrations  of  geometric  propositions  or  solution  of  geometric 
problems.*  Symbols  too  are  employed,  not  only  for  unknown  quantities, 
of  which  the  value  is  sought;  but  for  variable  quantities  of  which  the  value 
may  be  arbitrarily  put,  (F/;.  Ch.  6,  note  on  commencement  of  §  153 — 156,)and, 
especially  in  demonstrations,  for  both  given  and  sought  quantities.  Initials  of 
the  terms  for  square  and  solid  respectively  denote  those  powers ;  and  combined 
they  indicate  the  higher.  These  are  reckoned  not  by  the  sums  of  the 
powers;  but  by  their  products.^  An  initial  .syllable  is  in  like  manner  used 
to  mark  a  surd  root."  The  terms  of  a  compound  quantity  are  ordered  ac- 
cording to  the  powers;  and  the  absolute  number  invariably  comes  last.  It 
also  is  distinguished  by  an  initial  syllable,  as  a  discriminative  token  of 
known  quantity.'  Numeral  coefficients  are  employed,  inclusive  of  unity 
■which  is  always  noted,  and  comprehending  fractions;'"  for  the  numeral  divisor 
is  generally  so  placed,  rather  than  under  the  symbol  of  the  unknown  :  and  in 
like  manner  the  negative  dot  is  set  over  the  numeral  coefficient :  and  not 
over  the  literal  character.     The  coefficients  are  placed  after  the  symbol  of  the 

'  Vlj.-gan.  and  Brahm,  18,  passim.         *  Vij.-gan.  §  55.         '  Vij.-gan.  §  17.     Brahm.  c.  18,  §  2. 
♦  Vij.'gan.  ch.  6.  '  Vij-San-  §111.         *  ^'ij--gati.  §  U6. 

»  Li/.  §  26,  "  nj.-gan.  §  59.         »  Vij.-gan.  §  17. 

'°  Stevinu$  in  lilce. manner  included  fractions  in  coefficients, 

C2 


xli  DISSERTATION. 

unknown  quantity.*  Equations  are  not  ordered  so  as  to  put  all  the  quanti- 
ties positive;  nor  to  give  precedence  to  a  positive  term  in  a  compound  (jiian- 
tity :  lor  the  negative  terms  are  retained,  and  even  preferably  put  in  the  first 
place.  In  stating  the  two  sides  of  an  equation,  the  general,  though  not  inva- 
riable, practice  is,  at  least  in  the  first  instance,'^to  repeat  every  term,  which 
occurs  in  the  one  side,  on  the  other:  annexing  nought  for  the  coefficient,  if  a 
term  of  that  particular  denomination  be  there  wanting. 

If  reference  be  made  to  the  writings  of  Diophantus,  and  of  the  Arabian 
algebraists,  and  their  early  ilisciples  in  Europe,  it  will  be  found,  that  the 
notation,  which  has  been  here  described,  is  essentially  different  from  all 
theirs;  much  as  they  vary.  Diophantus  employs  the  inverted  medial  of 
iXAii4'»f,  defect  or  want  (opposed  to  vir»(^n,  substance  or  abundance")  to  indi- 
cate a  negative  quantity.  lie  prefixes  that  mark  '|»  to  the  quantity  in  ques- 
tion. He  calls  the  unknown,  x^iifA^;  representing  it  by  the  final  j,  which 
he  doubles  for  the  plural;  while  the  Arabian  algebraists  apply  the  equiva- 
lent word  for  number  to  the  constant  or  known  term;  and  the  Hindus,  on 
the  other  hand,  refer  the  word  for  numerical  character  to  the  coefficient. 
Pie  denotes  the  moniid,  or  unit  absolute,  by  jm*;  and  the  linear  quantity  is  called 
by  him  arithmos;  and  designated,  like  the  unknown,  by  the  im^Xsigma.  He 
marks  the  further  powers  by  initials  of  words  signifying  them:  S",  x",  SS",  ix", 
xx",  &c.  for  dynamis,  power  (meaning  the  scpiare) ;  cubos,  cube;  dynamo- 
ilynamis,  biquadrate,  &c.  But  he  reckons  the  higher  by  the  sums,  not  the 
products,  of  the  lower.  Thus  the  sixth  power  is  with  him  the  cuho-cubos, 
which  the  Hindus  designate  as  the  quadrate-cube,  (cube  of  the  square,  or 
square  of  the  cube). 

The  Arabian  Algebraists  are  still  more  sparing  of  symbols,  or  rather  entirely 
destitute  of  them.*  They  have  none,  whether  arbitrary  or  abbreviated,  either 
for  quantities  known  or  unknown,  positive  or  negative,  or  for  the  steps  and 
operations  of  an  algebraic  process :  but  express  every  thing  by  words,  and 
phrases,  at  full  length.  Their  European  scholars  introduced  a  'icwf  and  \ery 
few  abbreviations  of  names:  c",  c°,  c",  for  the  three  first  powers;  c*,  q*,  for 
the  first  and  second   unknown  quantities ;  p,  m,  for  plus  and  miims ;  and 

'  ViETA  ilid  so  likewise. 

*  A  word  of  nearly  the  same  import  with  the  Sanscrit  d'huna,  wealth,  used  by  /iwic/w  algebraists 
for  the  same  signification. 

*Def.  9.  ♦  As.  Res.  12.  183. 


DISSERTATION.  xiJi 

'Jjt  for  the  note  of  radicality  ;  occur  in  the  first  printed  work  which  is  that  of 
Paciolo.'  Leonardo  13oxacci  of  Pisa,  the  earliest  scholar  of  the  Arabians,* 
is  said  by  Targiom  Tozzkxti  to  have  used  the  small  letters  of  the  alphabet 
to  denote  quantities.'  But  Leonardo  only  does  so  because  he  represents 
quantities  by  straight  lines,  and  designates  those  lines  by  letters,  in  elucidation 
of  his  Algebraic  solutions  of  problems.* 

The  Arabians  termed  the  unknown  (and  they  wrought  but  on  one)  sfiai 
thing.  It  is  translated  by  Leonardo  oi' Pisa  and  his  disciples,  by  the  corre- 
spondent Latin  word  res  and  Italian  cosa  ;  whence  Regola  de  la  Cosa,  and 
Rule  of  Coss,  with  Cossike  practise  and  Cossike  number  of  our  older  authors,* 
for  Algebra  or  Speculative  practice,  as  Paciolo*  denominates  the  analytic 
art ;  and  Cossic  number,  in  writers  of  a  somewhat  later  date,  for  the  root  of 
an  c(iuation. 

The  Arabs  termed  the  square  of  the  unknown  mdl,  possession  or  wealth  ; 
translatetl  by  the  Latin  ccfisus  and  Italian  censo  ;  as  terms  of  the  same  import : 
for  it  is  in  the  acceptation  of  amount  of  property  or  estate^  that  census  was 
here  used  by  Leonardo. 

The  cube  was  by  the  Arabs  termed  Cub,  a  die  or  cube  ,•  and  they  combined 
these  terms  mul  and  cab  for  compound  names  of  the  more  elevated  powers; 
in  the  manner  of  Diophantus  by  the  sums  of  the  powers ;  and  not  like  the 
Hindus  by  their  products.  Such  indeed,  is  their  method  in  the  modern  ele- 
mentary works  :  but  it  is  not  clear,  that  the  same  mode  was  obsei-ved  by  their 
earlier  writers;  for  their  Italian  scholars  denominated  the  biquadrate  and 
higher  powers  Relato  primo,  secundo,  tcrtio,  &c. 

Positive  they  call  zaid  additional ;  and  negative  nakis  deficient :  and,  as 
before  observed,  they  have  no  discriminative  marks  for  either  of  them. 

The  operation  of  restoring  negative  quantities,  if  any  there  be,  to  the  po- 
sitive form,  which  is  an  essential  step  with  them,  is  termed  jei/',  or  with  the 
article  Aljebr,  the  mending  or  restoration.  That  of  coinparing  the  terms  and 
taking  like  from  like,  which  is  the  next  material  step  in  the  process  of  resolu- 


•  Or  Pacioli,  Paciuolo, — li,  &c.     For  the  namo  is  variously  written  by  Italian  authors. 

*  See  Note  L. 

'   V'laggi,  2d  Edit.  vol.  2,  p.  62. 

♦  CossALl,  Origine  dfU'Algebia,  i. 

'   Robert  Recorde's  Whetstone  of  Witte. 

*  Secondo  noi  delta  Pratica  Speculativa.     SummaS.  1. 
'  Census,  quicquid  fortunaruin  quis  habet.     Steph.  T/us. 


xiv  DISSERTATION. 

tion,  is  called  by  them  mukabalah  comparison.  Hence  the  name  of  Tarik 
aljebr  wa  almukahala,  '  the  method  of  restoration  and  comparison,'  which  ob- 
tained among  the  Arabs  for  this  branch  of  the  Analytic  art ;  and  hence  our 
name  of  Algebra,  from  Leonardo  of  Pisas  exact  version  of  the  Arabic  title. 
Fi  istakhruju'l  tnajhulut  ba  tarik  aljebr  wa  almukdbatah,'  De  solutione  qua- 
rundam  qua^stionum  secundum  modum  Algebra  et  Almuchabala." 

The  two  steps  or  operations,  which  have  thus  given  name  to  the  method  of 
analysis,  are  precisely  what  is  enjoined  without  distinctive  appellations  of 
them,  in  the  introduction  of  the  arithmetics  of  Diopiiantus,  where  he  directs, 
that,  if  the  quantities  be  positive  on  both  sides,  like  are  to  be  taken  from 
like  until  one  species  be  equal  to  one  species ;  but,  if  on  either  side  or  on 
both,  any  species  be  negative,  the  negative  species  must  be  added  to  both  sides, 
$0  that  they  become  positive  on  both  sides  of  the  equation  :  after  which  like 
are  again  to  be  taken  from  like,  until  one  species  remain  on  each  side. ' 

The  Hindu  Algebra,  not  requiring  the  terms  of  the  equation  to  be  all  ex- 
hibited in  the  form  of  positive  quantity,  does  not  direct  the  preliminary  step 
of  restoring  negative  quantity  to  the  affirmative  state:  but  proceeds  at  once 
to  the  operation  of  equal  subtraction  (samasudkana)  for  the  difference  of  like 
terms  which  is  the  process  denominated  by  the  Arabian  Algebraists  comparison 
(mukabalah).  On  that  point,  therefore,  the  Arabian  Algebra  has  more  affinity 
to  the  Grecian  than  to  the  Indian  analysis. 

As  to  the  progress  which  the  Hindus  had  made  in  the  analytic  art,  it  will 
be  seen,  that  they  possessed  w^ell  the  arithmetic  of  surd  roots  ;*  that  they  were 
aware  of  the  infinite  quotient  resulting  from  the  division  of  finite  quantity 
by  cipher ;'  that  they  knew  the  general  resolution  of  equations  of  the  second 
degree ;  and  had  touched  upon  those  of  higher  denomination  ;  resolving  them 
in  the  simplest  cases,  and  in  those  in  which  the  solution  happens  to  be  prac- 
ticable by  the  method  which  serves  for  quadratics  :*  that  they  had  attained  a 
general  solution  of  indeterminate  problems  of  the  first  degree :'  that  they  had 
arrived  at  a  method  for  deriving  a  multitude  of  solutions  of  answers  to  pro- 


•  KhuUsatiilhisAb.  c.  8.     Calcutta. 

*  Liber  abbaci,  9.  15.  3.     M.S.  in  Magliab.  Libr. 
»  Def.  U. 

♦  Brahm.  18.  |  27—29.    Vij.-gaii.  §  29—52. 
»  Lil.  S  45.  V'lj.-gaii.  \  15— 16  and  §  135. 

*  Vij-gad.  i  129.  and  §  137—138. 

'  Brahm.  18.  §  3—18.     ViJ.-gan.  53—73.    Lil.  §  2*8—265. 


DISSERTATION.  xv 

blems  of  the  second  degree  from  a  single  answer  found  tentatively  ;*  which 
is  as  near  an  approach  to  a  general  solution  of  such  problems,  as  was  made 
until  the  days  of  Lagrange,  who  first  demonstrated,  that  the  problem,  on 
which  the  solutions  of  all  questions  of  this  naturedepend,  is  always  resolvable 
in  whole  numbers."  The  Hindus  had  likewise  attempted  problems  of  this 
higher  order  by  the  application  of  the  method  which  suffices  for  those  of  the 
first  degree ;'  with  indeed  very  scanty  success,  as  might  be  expected. 

They  not  only  applied  algebra  both  to  astronomy*  and  to  geometry  ;*'  but 
conversely  applied  geometry  likewise  to  the  demonstration  of  Algebraic  rules.* 
In  short,  they  cultivated  Algebra  much  more,  and  with  greater  success,  than 
geometry ;  as  is  evident  from  the  comparatively  low  state  of  their  knowledge 
in  the  one,^  and  the  high  pitch  of  their  attainments  in  the  other :  and  they 
cultivated  it  for  the  sake  of  astronomy,  as  they  did  this  chiefly  for  astro- 
logical purposes.  The  examjjles  in  the  earliest  algebraic  treatise  extant 
(Brahmegupta's)  are  mostly  astronomical :  and  here  the  solution  of  indeter- 
minate problems  is  sometimes  of  real  and  practical  use.  The  instances  in  the 
later  treatise  of  Algebra  by  Bha'scara  are  more  various :  many  of  them  geo- 
metric ;  but  one  astronomical ;  the  rest  numeral :  among  which  a  great  number 
of  indeterminate  ;  and  of  these  some,  though  not  the  greatest  part,  resembling 
the  questions  which  chiefly  engage  the  attention  of  Diophantus.  But  the 
general  character  of  the  Diophantine  problems  and  of  the  Hindu  unlimited 
ones  is  by  no  means  alike  :  and  several  in  the  style  of  Diophantine  are  noticed 
by  Bhascara  in  his  arithmetical,  instead  of  his  algebraic,  treatise.* 

To  pursue  this  summary  comparison  further,  Diophantus  appears  to  have 
been  acquainted  with  the  direct  resolution  of  affected  quadratic  equations; 
but  less  familiar  with  the  management  of  them,  he  seldom  touches  on  it. 
Chiefly  busied  with  indeterminate  problems  of  the  first  degree,  he  yet  seems 
to  have  possessed  no  general  rule  for  their  solution.  His  elementary  in- 
structions for  the  preparation  of  equations  are  succinct.'     His  notation,  as 


■  Brahn.  18.  §  29—49.     Vij.-gan.  §  75—99.  *  Mem.  of  Acad,  of  Turin  :  and  of  Berlin. 

'   Fy.-gan.  §  206—207.  *  Crrt/iw.  18.  passim.   Vij.-gan. 

'   Vij.-gan.  §117—127.  h  146—152.  «  Vij.-gan.  §  212—214. 

'  Bruhm.  12.  S  21  ;  corrected  however  in  Lil.  §  169— 170. 

*  Lil.  §  59 — 61,  where  it  appears,  however,  that  preceding  writers  liad  treated  the  question  alge- 
braically.    See  likewise  §  139 — 146. 
»  Def.  1 1. 


xvi  DISSERTATION. 

before  observed,  scanty  and  inconvenient.  In  tbc  whole  science,  he  is  veiy 
far  behind  the  Hindu  writers:  notwithstanding  the  infinite  ingenuity,  by 
which  he  makes  up  for  the  want  of  rule:  and  althougli  presented  to  us  under 
the  disadvantage  of  mutilation ;  if  it  be,  indeed,  certain  that  the  text  of  only 
six,  or  at  most  seven,  of  thirteen  books  which  his  introduction  announces,  has 
been  preserved.'  It  is  sufficiently  clear  from  what  does  remain,  that  the  lost 
part  could  not  have  exhibited  a  much  higher  degree  of  attainment  in  the  art. 
It  is  presumable,  that  so  much  as  we  possess  of  his  work,  is  a  fair  specimen 
of  the  progress  which  he  and  the  Greeks  before  him  (for  he  is  hardly  to  be 
considered  as  the  inventor,  since  he  seems  to  treat  the  art  as  already  known ;) 
had  made  in  his  time. 

The  points,  in  which  the  Hindu  Algebra  appears  particularly  distinguished 
from  the  Greek,  are,  besides  a  better  and  more  comprehensive  algorithm, — 
1st,  The  management  of  equations  involving  more  than  one  unknown  term. 
(This  adds  to  the  two  classes  noticed  by  the  Arabs,  namely  simple  and  com- 
pound, two,  or  rather  three,  other  classes  of  equation.)  2d,  The  resolution 
of  equations  of  a  higher  order,  in  which,  if  they  achieved  little,  they  had,  at 
least,  the  merit  of  the  attempt,  and  anticipated  a  modern  discovery  in  the 
solution  of  biquadratics.  3d,  General  methods  for  the  solution  of  indeter- 
minate problems  of  1st  and  2d  degrees,  in  which  they  went  far,  indeed, 
beyond  Diophantus,  and  anticipated  discoveries  of  modern  Algebraists. 
4th,  Application  of  Algebra  to  astronomical  investigation  and  geometrical 
demonstration :  in  which  also  they  hit  upon  some  matters  which  have  been 
reinvented  in  later  times. 

This  brings  us  to  the  examination  of  some  of  their  anticipations  of  modem 
discoveries.  The  readers  notice  will  be  here  drawn  to  three  instances  in 
particular. 

The  first  is  the  demonstration  of  the  noted  proposition  of  Pythagoras, 
concerning  the  square  of  the  base  of  a  rectangular  triangle,  equal  to  the 
squares  of  the  two  legs  containing  a  right  angle.  The  demonstration  is  given 
two  ways  in  Bha'scara's  Algebra,  {Vrj.-gaiL  §  146.)  The  first  of  them  is  the 
same  which  is  delivered  by  Wallis  in  his  treatise  on  angular  sections,  (Ch. 
6.)  and,  as  far  as  appears,  then  given  for  the  first  time.* 

'  Note  M.  *  He  designates  the  sides  C.  D.    Base  B.    Segments  «,  i.    Then 

B:C::C:«1        ,.       .        f  C'=Bk 
B:D::D:Jr'"^'^"^^''^{D.=B* 


DISSERTATION.  xvii 

On  the  subject  of  demonstrations,  it  is  to  be  remarked  that  the  Hindu  ma- 
thematicians proved  propositions  both  algebraically  and  geometrically  :  as  is 
particularly  noticed  by  Bha'scaua  himself,  towards  the  close  of  his  Algebra, 
where  he  gives  i)oth  modes  of  proof  of  a  remarkable  method  for  the  solution 
of  indeterminate  problems,  which  involve  a  factum  of  two  unknown  quan- 
tities. The  rule,  which  he  demonstrates,  is  of  great  antiquity  in  Hindu 
Algebra:  being  found  in  the  works  of  his  predecessor  Brahjiegupta,  and 
being  there  a  quotation  from  a  more  ancient  treatise ;  for  it  is  injudiciously 
censured,  and  a  less  satisfactory  method  by  unrestricted  arbitrary  assumption 
given  in  its  place.     Bha'scara  has  retained  both. 

The  next  instance,  which  will  be  here  noticed,  is  the  general  solution  of  in- 
determinate problems  of  the  first  degree.  It  was  first  given  among  moderns 
by  Bachet  de  Meziriac  in  1624.*  Having  shown  how  the  solution  of 
equations  of  the  form  ax—by=c  is  reduced  to  ax—by=  +  \,  he  proceeds  to 
resolve  this  equation:  and  prescribes  the  same  operation  on  a  and  b  as  to  find 
the  greatest  common  divisor.  He  names  the  residues  c,  d,  e,  f,  &c.  and  the 
last  remainder  is  necessarily  unity :  a  and  b  being  prime  to  each  other.  By 
retracing  the  steps  from  eipi  or^+l  (.iccordiug  as  the  number  of  remainders 
is  even  or  odd)  e+l=£,  sd±i  =<?,  Jc+l  =y,  yb±l  =p,  !3a+ 1  =a 

e  d  c  b 

or/±l=C,  C£+i  =«.  «</±l  f,  &c. 

/ 
The  last  numbers  |3  and  a  will  be  the  smallest  values  of  .i'  and  y.     It  is  ob- 
served, that,  if  a  and  b  be  not  prime  to  each  other,  the  equation  cannot 
subsist  in  whole  numbers  unless  c  be  divisible  by  the  greatest  common  mea- 
sure of  a  and  b. 

Here  we  have  precisely  the  method  of  the  Hindu  algebraists,  who  have 
not  failed,  likewise,  to  make  the  last  cited  observation.     See  Brahm.  Algebra, 


Therefore  C*-f-D*=(B«+B  *=B  into  «+>=)  B*. 
The  Indian  demonstration,  with  the  same  symbols,  is 

B:D::D:>;  ^  ,^  g^ 

B 

Therefore  B=ii-|-J=C*-|-D»  and  B'=C'+D'. 
B"     ¥ 

'  Problfemes  plaisans  et  delectables  qui  se  font  par  les  nombres.   2d  Edit.  (1624).     Lagbange's 
additions  to  Euler's  Algebra,  ij.  382.  (Edit.  1807.) 

d 


xviii  DISSERTATION. 

section  1.  and  Bhdsc.  Lil.  ch.  12.  Vy.  ch.  2.  It  is  so  prominent  in  the 
Indian  Algebra  as  to  give  name  to  the  oldest  treatise  on  it  extant ;  and  to 
constitute  a  distinct  head  in  the  enumeration  of  the  different  branches  of 
mathematical  knowledge  in  a  passage  cited  from  a  still  more  ancient  author. 
See  Lii.  §  248. 

Confining  the  comparison  of  Hindu  and  modem  Algebras  to  conspicuous 
instances,  the  next  for  notice  is  that  of  the  solution  of  indeterminate  pro- 
blems of  the  2d  degree:  for  which  a  general  method  is  given  by  Brahmk- 
GUPTA,  besides  rules  for  subordinate  cases:  and  two  general  methods  (one  of 
them  the  same  with  Urahmegupta's)  besides  special  cases  subservient 
however  to  the  universal  solution  of  problems  of  this  nature ;  and,  to  obtain 
whole  numbers  in  all  circumstances,  a  combination  of  the  method  for  pro- 
blems of  the  first  degree  with  that  for  those  of  the  second,  employing  them 
alternately,  or,  as  the  Hindu  algebraist  terms  it,  proceeding  in  a  circle. 

Bha'scara's  second  method  {Vij.  §  80 — 81)  for  a  solution  of  the  problem  on 
which  all  indeterminate  ones  of  this  degree  depend,  is  exactly  the  same,  which 
Lord  Brouncker  devised  to  answer  a  question  proposed  by  way  of  challenge 
by  Fermat  in  1657.  The  thing  required  was  a  general  rule  for  finding  the 
innumerable  square  numbers,  which  multiplied  by  a  proposed  (non-quadrate) 
number,  and  then  assuming  an  unit,  will  make  a  square.  Lord  Brouncker's 
rule,  putting  n  for  any  given  number,  r"  for  any  square  taken  at  pleasure, 

and  d  for  difference  between  n  and  r^  (r*  c/3  n)  was— ir  (  ~"Z   V  J  *^^  square 

2  r 

required.     In  the  Hmdu  rule,  usmg  the  same  symbols,  -j  is  the  square  root 

required.*  But  neither  Brouncker,  nor  Wallis,  who  himself  contrived 
another  method,  nor  Fkrmat,  by  whom  the  question  was  proposed,  but  whose 
mode  of  solution  was  never  made  known  by  him,  (probably  because  he  had  not 
found  anything  better  than  Wallis  and  Brouncker  discovered,*)  nor  Fre- 
NrcLE,  who  treated  the  subject  without,  however,  adding  to  what  had  been 
done  by  Wallis  and  Brouncker,'  appear  to  have  been  aware  of  the  impor- 
tance of  the  problem  and  its  universal  use :  a  discovery,  which,  among  the 
moderns,  was  reserved  for  Euler  in  the  middle  of  the  last  century.  To  him, 
among  the  moderns,  we  owe  the  remark,  which  the  Hindus  had  made  more 
than  a  thousand  years  before,*  tliat  the  problem  was  requisite  to  find  all  the 

^  ^  yij.-gati.^  80 ~8\.  »  Wallis,  Alg.  c.  98.  Mbid. 

•  ♦  BMscara  Vij.  §  173,  and  §  207.    See  Ifkewise  Brahm.  Alg.  sect.  7. 


DISSERTATION.  xix 

possible  solutions  of  equations  of  this  sort.  Lagrange  takes  credit  for 
having  further  advanced  the  progress  of  this  branch  of  the  indeterminate 
analysis,  so  lately  as  1767;'  and  his  complete  solution  of  equations  of  the 
2d  degree  appeared  no  earlier  than  I769.- 

It  has  been  pretended,  that  traces  of  the  art  are  to  be  dicovered  in  the 
writings  of  the  Grecian  geometers,  and  particularly  in  the  five  first  proposi- 
tions of  Euclid's  thirteenth  book ;  whether,  as  Wallis  conjectures,  what 
we  there  have  be  the  work  of  Theox  or  some  other  antient  scholiast,  rather 
than  of  Euclid  himself:^  Also  examples  of  analytic  investigation  in  Pap- 
pus ;♦  and  indications  of  a  method  somewhat  of  a  like  nature  with  algebra, 
or  at  least  the  effects  of  it,  in  the  works  of  Archimedes  and  Apollonius; 
though  they  are  supposed  to  have  very  studiously  concealed  this  their  art  of 
invention.' 

This  proceeds  on  the  ground  of  considering  Analysis  and  Algebra,  as  in- 
terchangeable terms  ;  and  applying  to  Algebra  Euclid's  or  Theon's  defini- 
tion of  Analysis,  '  a  taking  of  that  as  granted,  which  is  sought;  and  thence 
by  consequences  arriving  at  what  is  confessedly  true.'* 

Undoubtedly  they  possessed  a  geometrical  analysis;  hints  or  traces  of 
which  exist  in  the  writings  of  more  than  one  Greek  mathematician,  and 
especially  in  those  of  Archimedes.  But  this  is  very  diflFerent  from  the 
Algebraic  Calculus.  The  resemblance  extends,  at  most,  to  the  method  of 
inversion ;  which  both  Hindus  and  Arabians  consider  to  be  entirely  distinct 
from  their  respective  Algebras ;  and  which  the  former,  therefore,  join  with 
their  arithmetic  and  mensuration.^ 

In  a  very  general  sense,  the  analytic  art,  as  Hin<lu  writers  observe,  is 
merely  sagacity  exercised ;  and  is  independent  of  symbols,  which  do  not 
constitute  the  art.  In  a  more  restricted  sense,  according  to  them,  it  is  cal- 
culation attended  with  the  manifestation  of  its  principles :  and,  as  they  fur- 
ther intimate,  a  method  aided  by  devices,  among  which  symbols  and  literal 
signs  are  conspicuous.'     Defined,  as  analysis  is  by  an  illustrious  modern 

'  Mem.  de  I'Acad.  de  Berlin,  vol.  24. 

*  See  French  translation  of  Euler's  Algebra,  Additions,  p.  286.     And  Legetidre  Theorie  de« 
Nombres  1 .  §  6.  No.  36. 
'  Wau.i«,  Algebra,  c,  2.  *  Ibid,  and  Preface. 

»  Ibid,  and  Nunez  Algebra  1)4.  *  Wallis,  following  Vibta's  version,  Alg,  c,  1. 

'  Lil.  3.  1.  §  47.     KhuUimt.  Iliidb.  c.  5.  »  f^V-'g"*-  §  "0,  1/4,  215,  224. 

d  2 


XX  DISSERTATION. 

mathematician,'  '  a  method  of  resolving  mathematical  problems  by  reducing^ 
them  to  equations,'  it  assuredly  is  not  to  be  found  in  the  works  of  any 
Grecian  writer  extant,  besides  Diophaxtus. 

In  his  treatise  the  rudiments  of  Algebra  are  clearly  contained.  He  deli- 
vers in  a  succinct  manner  the  Algorithm  of  affirmative  and  negative  quanti- 
ties; teaches  to  form  an  equation;  to  transpose  the  negative  terms  ;  and  to 
bring  out  a  final  simple  equation  comprising  a  single  term  of  each  species 
known  and  unknown. 

Admitting  on  the  ground  of  the  mention  of  a  mathematician  of  his  name, 
whose  works  were  commented  by  Hvpatia  about  the  beginning  of  the  fifth 
century  f  and  on  the  authority  of  the  Arabic  annals  of  an  Armenian  Chris- 
tian;' which  make  him  contemporary  with  Julian;  that  he  lived  towards 
the  middle  of  the  fourth  century  of  the  Christian  era;  or,  to  speak  with  pre- 
cision, about  the  year  360  ;*  the  Greeks  will  appear  to  have  possessed  in 
the  fourth  century  so  much  of  Algebra,  as  is  to  be  eflfected  by  dexterous 
application  of  the  resolution  of  equations  of  the  first  degree,  and  even  the 
second,  to  limited  problems;  and  to  indeterminate  also,  without,  however, 
having  attained  a  general  solution  of  problems  of  this  latter  class. 

The  Arabs  acquired  Algebra  extending  to  simple  and  compound  (meaning 
quadratic)  equations;  but  it  was  confined,  so  far  as  appears,  to  limited  pro- 
blems of  tliose  degrees :  and  they  possessed  it  so  early  as  the  close  of  the 
eighth  century,  or  commencement  of  the  ninth.  Treatises  were  at  that 
period  written  in  the  Arabic  language  on  the  Algebraic  Analysis,  by  two 
distinguished  mathematicians  who  flourished  under  the  Abbasside  ALMA'jiu'if  r 
and  the  more  ancient  of  the  two,  Muhaimmed  Bf:N  Mlsa  Al  Khuzcdrezmi, 
is  recognised  among  the  Arabians  as  the  first  who  made  Algebra  known  to 
them.  He  is  the  same,  who  abridged,  for  the  gratification  of  Alma'mu'n,  an 
astronomical  work  taken  from  the  Indian  system  in  the  preceding  age,  under 
Almansur.  He  framed  tables  likewise,  grounded  on  those  of  the  Hindus; 
which  he  professed  to  correct.     And  he  studied  and  connnunicatcd  to  his 


■  D'Alembert.  *  SuiDAS,  in  voce  Hypatia. 

'  Gregory  Abulfaraj.  Ex  iis  etiain  [nempe  philosopliis  qui  prope  tempera  .Tuliani  florue- 
runt]  Diophantus,  cujus  liber,  quern  Algebram  vocant,  Celebris  est,  in  qnem  si  imniiserit  se  Lector, 
oceanum  hoc  in  genere  reperiet. — Pococke. 

*  Julian  was  emperor  from  SfiO  to  363.     Sec  nuie  M. 


DISSERTATION.  xxi 

countrymen  the  Indian  compendious  method  of  computation  ;  that  is,  their 
arithmetic,  and,  as  is  to  be  inferred,  tlieir  analytic  calculus  also.' 

The  Hindus  in  the  fifth  century,  perhaps  earliei,-  were  in  possession  of 
Algebra  extending  to  the  general  solution  of  both  determinate  and  indeter- 
minate problems  of  the  1st  and  2d  degrees :  and  subsequently  advanced  to 
the  special  solution  of  biquadratics  wanting  the  second  term  ;  and  of  cubics 
in  very  restricted  and  easy  cases. 

Priority  seems  then  decisive  in  favour  of  both  Greeks  and  Hindus  against 
any  pretensions  on  the  part  of  the  Arabians,  who  in  fact,  however,  prefer 
none,  as  inventors  of  Algebra.  They  were  avowed  borrowers  in  science: 
and,  by  their  own  unvaried  acknowledgment,  from  the  Hindus  they  learnt 
the  science  of  numbers.  That  they  also  received  the  Hindu  Algebra,  is 
much  more  probable,  than  that  the  same  mathematician  who  studied  the 
Indian  arithmetic  and  taught  it  to  liis  Arabian  brethren,  should  have  hit 
upon  Algebra  unaided  by  any  hint  or  suggestion  of  the  Indian  analysis. 

The  Arabs  became  accjuainted  with  the  Indian  astronomy  and  numerical 
science,  before  they  had  any  knowledge  of  the  writings  of  the  Grecian  as- 
tronomers and  mathematicians :  and  it  was  not  until  after  more  than  one 
century,  and  nearly  two,  that  they  had  the  benefit  of  an  interpretation  of 
Diophantus,  whether  version  or  paraphrase,  executed  by  Muhammed 
Abulwafa  Al  Buzjani;  who  added,  in  a  separate  form,  demonstrations  of 
the  propositions  contained  in  Diophantus;  and  who  was  likewise  author  of 
Commentaries  on  the  Algebraic  treatises  of  the  Khuwarezviite  AIuhammed 
BEN  Mlsa,  and  of  another  Algebraist  of  less  note  and  later  date,  Abi  Yahva, 
whose  lectures  he  had  personally  attended.'  Any  inference  to  be  drawn 
from  their  knowledge  and  study  of  the  Arithmetics  of  Diophantus  and 
their  seeming  adoption  of  his  preparation  of  equations  in  their  own  Algebra, 
or  at  least  tlie  close  resemblance  of  both  on  this  point,  is  of  no  avail  against 
the  direct  evidence,  with  which  we  arc  furnished  by  them,  of  previous  in- 
struction in  Algebia  and  the  publication  of  a  treatise  on  the  art,  by  an  author 
conversant  with  the  Indian  science  of  computation  in  all  its  branches. 

But  the  age  of  the  earliest  known  Hindu  writer  on  Algebra,  not  being 
with  certainty  carried  to  a  period  anterior,  or  even  quite  equal  to  that  in 
which  DioPHANTLS  is  on  probable  grounds  placed,  the  argument  of  priority, 
so  far  as  investigation  has  yet  proceeded,  is  in  favour  of  Grecian  invention. 

■  Note  N.  ^  See  note  I.  ^  See  note  N. 


xxU  DISSERTATION. 

The  Hindus,  however,  had  certainly  made  distinguished  progress  in  the 
science,  so  early  as  the  century  immediately  following  that  in  which  the 
Grecian  taught  the  rudiments  of  it.  The  Hindus  had  the  benefit  of  a  good 
arithmetical  notation :  the  Greeks,  the  disadvantage  of  a  bad  one.  Nearly 
allied  as  algebra  is  to  arithmetic,  the  invention  of  the  algebraic  calculus  was 
more  easy  and  natural  where  arithmetic  was  best  handled.  No  such  marked 
identity  of  the  Hindu  and  Diophantine  systems  is  observed,  as  to  demon- 
strate communication.  They  are  sufficiently  distinct  to  justify  the  pre- 
sumption, that  both  might  be  invented  independently  of  each  other. 

If,  however,  it  be  insisted,  that  a  hint  or  suggestion,  the  seed  of  their  know- 
ledge, may  have  reached  the  Hindu  mathematicians  immediately  from  the 
Greeks  of  Alexandria,  or  mediately  through  those  of  Bactria,  it  must  at  the 
same  time  be  confessed,  that  a  slender  germ  grew  and  fructified  rapidly,  and 
soon  attained  an  approved  state  of  maturity  in  Indian  soil. 

More  will  not  be  here  contended  for:  since  it  is  not  inijxjssible,  that  the  hint 
of  the  one  analysis  may  have  been  actually  received  by  the  mathematicians  of 
the  other  nation;  nor  unlikely,  considering  the  arguments  which  may  be 
brought  for  a  probable  communication  on  the  subject  of  astrology;  and  ad- 
verting to  the  intimate  connexion  between  this  aud  the  pure  mathematics, 
through  the  medium  of  astronomy. 

The  Hindus  had  undoubtedly  made  some  progress  at  an  early  period  in 
the  astronomy  cultivated  by  them  for  the  regulation  of  time.  Their  calen- 
dar, both  civil  and  religious,  was  governed  chiefly,  not  exclusively,  by  the 
moon  and  sun:  and  the  motions  of  these  luminaries  were  carefully  observed 
by  them:  and  with  such  success,  that  their  determination  of  the  moon's 
synodical  revolution,  which  was  what  they  were  principally  concerned  with, 
is  a  much  more  correct  one  than  the  Greeks  ever  achieved.^  They  had  a 
division  of  the  ecliptic  into  twenty-seven  and  twenty-eight  parts,  suggested 
evidently  by  the  moon's  period  in  days;  and  seemingly  their  own:  it  was 
certainly  borrowed  by  the  Arabians."  Being  led  to  the  observation  of  the 
fixed  stars,  they  obtained  a  knowledge  of  the  positions  of  the  most  remark- 
able; and  noticed,  for  religious  purposes,  and  from  superstitious  notions,  the 
heliacal  rising,  with  other  phoenomena  of  a  few.  The  adoration  of  the  sun, 
of  the  planets,  and  of  the  stars,  in  common  with  the  worship  of  the  elements, 

•  As.  Res.  2  and  12.  *  As,  Res.  9,  Essay  vj. 


DISSERTATION.  xxiii 

held  a  principal  place  in  their  religious  observances,  enjoined  by  the  Vedas:^ 
and  they  were  led  consequently  by  piety  to  watch  the  heavenly  bodies. 
They  were  particularly  conversant  with  the  most  splendid  of  the  primary 
planets;  the  period  ot"  Jupiter  being  introduced  by  them,  in  conjunction  ' 
with  those  of  the  sun  and  moon,  into  the  regulation  of  their  calendar,  sacred 
and  civil,  in  the  form  of  the  celebrated  cycle  of  sixty  years,  common  to 
them  and  to  the  Chaldeans,  and  still  retained  by  them.  From  that  cycle 
they  advanced  by  progressive  stages,  as  the  Chaldeans  likewise  did,  to  larger 
periods  ;  at  first  by  combining  that  with  a  number  specifically  suggested  by 
other,  or  more  correctly  determined,  revolutions  of  the  heavenly  bodies  ;  and 
afterwards,  by  merely  augmenting  the  places  of  figures  for  greater  scope, 
(preferring  this  to  the  more  exact  method  of  combining  periods  of  the 
planets  by  an  algebraic  process;  which  they  likewise  investigated^):  until 
they  arrived  finally  at  the  unwieldy  cycles  named  Mahayugas  and  Calpas. 
But  it  was  for  the  sake  of  astrology,  that  they  pushed  their  cultivation  of 
astronomy,  especially  that  of  the  minor  planets,  to  the  length  alluded  to. 
Now  divination,  by  the  relative  position  of  the  planets,  seems  to  have  been, 
in  part  at  least,  of  a  foreign  growth,  and  comparatively  recent  introduction, 
among  the  Hindus.  The  belief  in  the  influence  of  the  planets  and  stars, 
upon  human  affairs,  is  with  them,  indeed,  remotely  antient;  and  was  a 
natural  consequence  of  their  creed,  which  made  the  sun  a  divine  being,  and 
the  planets  gods.  But  the  notion,  that  the  tendency  of  that  supposed  in-  . 
fluence,  or  the  manner  in  which  it  will  be  exerted,  may  be  foreseen  by  man, 
and  the  effect  to  be  produced  by  it  foretold,  through  a  knowledge  of  the  posi- 
tion of  the  planets  at  a  particular  moment,  is  no  necessary  result  of  that 
creed  :  for  it  takes  from  beings  believed  divine,  free-agency  in  other  respects, 
as  in  their  visible  movements. 

Whatever  may  have  been  the  period  when  the  notion  first  obtained,  that 
foreknowledge  of  events  on  earth  might  be  gained  by  observations  of  planets 
andstais,  and  by  astronomical  computation;  or  wherever  that  fancy  took  its 
rise;  certain  it  is,  that  the  Hindus  have  received  and  welcomed  communica- 
tions from  other  nations  on  topics  of  astrology:  and  although  they  had  astro- 
logical divinations  of  their  own  as  early  as  the  days  of  Paras'aka  and 
Garoa,  centuries  before  the  Christian  era,  there  are  yet  grounds  to  presume 

'  As.  Res.  8.  *  Brahmegupta,  Algebra. 


xxiv  DISSERTATION. 

that  communications  subsequently  passed  to  them  on  the  like  subject,  either 
from  the  Greeks,  or  from  the  same  common  source  (perhaps  that  of  the 
Chaldeans)  whence  the  Greeks  derived  the  grosser  superstitions  engrafted  on 
their  own  genuine  and  antient  astrology,  which  was  meteorological. 

This  opinion  is  not  now  suggested  for  the  first  time.  Former  occasions 
have  been  taken  of  intimating  the  same  sentiment  on  this  point:'  and  it  has 
been  strengthened  by  further  consideration  of  the  subject.  As  the  question 
is  closely  connected  with  the  topics  of  this  dissertation,  reasons  for  this 
opinion  will  be  stated  in  the  subjoined  note." 

Joining  this  indication  to  that  of  the  division  of  the  zodiac  into  twelve 
signs,  represented  by  the  same  figures  of  animals,  and  named  by  words  of  the 
same  import  with  the  zodiacal  signs  of  the  Greeks;  and  taking  into  consi- 
deration the  analogy,  though  not  identity,  of  the  Ptolemaic  system,  or  rather 
that  of  HippARCHUs,  and  the  Indian  one  of  excentric  deferents  and  epicycles, 
which  in  both  serve  to  account  for  the  irregularities  of  the  planets,  or  at  least 
to  compute  them,  no  doubt  can  be  entertained  tliatthe  Hindus  received  hints 
from  the  astronomical  schools  of  the  Greeks. 

It  must  then  be  admitted  to  be  at  least  possible,  if  not  probable,  in  the 
absence  of  direct  evidence  and  positive  proof,  that  the  imperfect  algebra  of 
the  Greeks,  which  had  advanced  in  their  hands  no  further  thau  the  solution 
of  equations,  involving  one  unknown  term,  as  it  is  taught  by  Diophantus, 
was  made  known  to  the  Hindus  by  their  Grecian  instructors  in  improved 
astronomy.  But,  by  the  ingenuity  of  the  Hindu  scholars,  the  hint  was 
rendered  fruitful,  and  the  algebraic  method  Avas  soon  ripened  from  that  slen- 
der beginning  to  the  advanced  state  of  a  well  arranged  science,  as  it  was 
taught  by  Auyabhatt'a,  and  as  it  is  found  in  treatises  compiled  by  Brah- 
MEGUPTA  and  Bha'scara,  of  both  which  versions  are  here  presented  to  the 
public. 

»  As.  Res.  12.  ♦  NoU  O. 


(       XXV       ) 


NOTES  AND  ILLUSTRATIONS. 


A. 

SCHOLIASTS   OF  BHASCARA. 

The  oldest  commentary  of  ascertained  date,  which  has  come  into  the 
translator's  hands,  and  has  been  accordingly  employed  by  him  for  the  pur- 
pose of  collation,  as  well  as  in  the  progress  of  translation,  is  one  composed 
by  Ganga'd'hara  son  of  Gobahd'haxa  and  grandson  of  Diva'cara, 
inhabitant  of  Jamhusara}  It  appears  from  an  example  of  an  astronomical 
computation,  which  it  exhibits,*  to  have  been  written  about  the  year 
1342  Saca  (A.  D.  1420).  Though  confined  to  the  Lilavati,  it  expounds  and 
consequently  authenticates  a  most  material  chapter  of  the  Vija-ganita, 
which  recurs  nearly  verbatim  in  both  treatises  ;  but  is  so  essential  a  part  of 
the  one,  as  to  have  given  name  to  the  algebraic  analysis  in  the  works  of  the 
early  writers.'  His  elder  brother  ViSHisfu  pandita  was  author  of  a  treatise 
of  arithmetic,  &c.  named  Ganita-sdra,  a  title  borrowed  from  the  compendium 
of  Srid'haea.     It  is  frequently  quoted  by  him. 

The  next  commentary  in  age,  and  consequent  importance  for  the  objects  now 
under  consideration,  is  that  of  Su'rya  suri  also  named  Su'ryada'sa,  native  of 
Pdrthapura,  near  the  confluence  of  the  Godd  and  Vidarbhd  rivers.*  He  was 
author  of  a  complete  commentary  on  the  Sidd hdnta-siromani ;  and  of  a  dis- 
tinct work  on  calculation,  under  the  title  of  Gaiiiia-mdlati ;  and  of  a  compi- 
lation of  astronomical  and  astrological  doctrines,  Hindu  and  Muhammedan, 
under  the  name  of  Sidd'hdiita-sanhitd-sdra-samuchchaya  ;  in  which  he  makes 
mention  of  his  commentary  on  the  Sirommii.     The  gloss  on  the  Lilavati,  en- 

•  A  town  situated  in  Gujrat  (Gurjara),  twenty-eight  miles  north  of  the  town  oi  Broach, 

»  Lll.  S  264. 

^  Cuttac&d'hjj/iya,  the  title  of  Braiimegupta's  chapter  on  Algebra,  and  of  a  chapter  in  AarA- 
biiatta's  work. 
.-ft*  GOdivari  and  WtrdL 

e 


xxvi  NOTES  AXD  ILLUSTRATIONS. 

titled  Ganitamrita,  and  that  on  the  Fjja-ganita,  named  Surya-pracdsa,  both 
excellent  works,  containing  a  clear  interpretation  of  the  text,  with  a  concise 
explanation  of  the  principles  of  the  rules,  are  dated  the  one  in  1460,  the  other 
in  1463  iiaca;  or  A.D.  1538  and  1541.  His  father  JsyA-VAaAJA,  son  of 
Nagaxa't'ha,  a  Brahmen  and  astronomer,  was  author,  among  other  works, 
of  an  astronomical  course,  under  the  title  of  Siddhanta-sundara,  still  extant,* 
which,  like  the  Siddhanta-slromatii,  comprises  a  treatise  on  algebra.  It  is 
repeatedly  cited  by  his  son. 

Gaxes'a,  son  of  Ce'sava,  a  distinguished  astronomer,  native  of  Nandi- 
grama,  near  Dfcagiri,  (better  known  by  the  Muhammedan  name  of  Daule- 
tabad)^  was  author  of  a  commentary  on  the  Sidi hanta-sirbmani,  which  is 
mentioned  by  his  nephew  and  scholiast  Nrisixha  ;  in  an  enumeration  of  his 
Avorks,  contained  in  a  passage  quoted  by  Vis'waxaV ha  on  the  Grahalaghara. 
His  commentary  on  the  Lildvati  bears  the  title  of  Budd'hhilasini,  and  date  of 
1467  ^aca,  or  A.  D.  1545.  It  comprises  a  copious  exposition  of  the  text, 
with  demonstrations  of  the  rules :  and  has  been  used  throughout  the  trans- 
lation as  the  best  interpreter  of  it  He,  and  his  father  Ces'ava,  and  nephew 
Nbisixha,  as  well  as  his  cousin  Lacshmi'dasa,  were  authors  of  numerous 
works  both  ou  astronomy  and  divination.  Tlie  most  celebrated  of  his  own 
performances,  the  Grahalaghava,  bears  date  1442  Saca,  answering  to  A.  D. 
1520. 

The  want  of  a  commentary  by  Gaxes'a  on  the  Vija-gaiiita,  is  supplied 
by  that  of  Chishxa,  son  of  Ballala,  and  pupil  of  Vishnu,  the  disciple  of 
Gaxes'a's  nephew  Nrisixha.  It  contains  a  clear  and  copious  exposition 
of  the  sense,  with  ample  demonstrations  of  the  rules,  much  in  the  manner  of 
Ganesa,  on  the  Lilavati ;  whom  also  he  imitated  in  composing  a  commen- 
tary on  that  treatise,  and  occasionally  refers  to  it.  His  work  is  entitled 
Calpalatavatdra.  Its  date  is  determined,  at  the  close  of  the  sixteenth 
century  of  the  Christian  era,  by  the  notice  of  it  and  of  the  author  in  a  work 
of  his  brother  RaxganaVha,  dated  1524  Saca  (A.D.  1602),  as  well  as  in 
one  by  his  nephew  McnxsVara.  He  appears  to  have  been  astrologer  in 
the  service  of  the  Emperor  Jeh  a'ngie,  who  reigned  at  the  beginning  of  the 
seventeenth  century. 

The  gloss  of  Raxgana't'ha  on  the  Vdsana,  or  demonstratory  annotations 

'  The  astronomical  part  is  in  the  library  of  the  East  India  Company. 

*  Naitdigrim  retains  its  ancient  name ;  and  is  situated  west  of  Dauktabad,  aboat  sixty-five  miles. 


SCHOLIASTS  OF  BHASCARA.  xxvit 

of  Bha'scara,  which  is  entitled  Mita-bhashini,  contains  no  specification  of 
date ;  but  is  determined,  with  sufficient  certainty,  towards  tlie  middle  of 
the  sixteenth  centun,-  of  the  Saca  era,  by  the  writer's  relation  of  son  to 
Nrisixha,  the  author  of  a  commentary  on  the  Surya-siddhanta,  dated 
1542  Saca,  and  of  the  Vasand-vdrtica  (or  gloss  on  Bha'scara's  annotations 
of  the  Siromani),  which  bears  date  in  \5^3  Saca,  or  A.D.  1621;  and  his 
relation  of  brother,  as  well  as  pupil,  to  Camalacara,  author  of  the  Siddhdnta- 
tatrca-vivica,  also  composed  towards  the  middle  of  the  same  centurj*  of 
the  Saca  era.  Nrisinha,  and  his  uncle  Viswana't'ha,  (author  of  astrolo- 
gical commentaries,)  describe  their  connnon  ancestor  Diva'cara,  and  his 
grandfather  Ra'ma,  as  Maharashtra  Brahmens,  living  at  Golagrdma,^  on 
the  northern  bank  of  the  Goddvari,  and  do  not  hint  a  migration  of  the 
family.  Nrisixha's  own  father,  Crishn'a,  was  author  of  a  treatise  on 
algebra  in  compendious  rules  (sutra),  as  his  son  affirms. 

The  Vija-prabodha,  a  commentary  on  the  Vija-ganita,  by  Ra'ma  Crishva, 
son  of  Lacsuman'a,  and  grandson  of  Nrisinha,  mhahxtixit  oi  Amardrati,* 
is  without  date  or  express  indication  of  its  period ;  unless  his  grandfather 
Nrisixha  be  the  same  with  the  nephew  of  Vis'wana't'ha  just  now  men- 
tioned: or  else  identified  with  the  nephew  of  Gan'e's'a  and  preceptor  of 
Vishnu,  the  instructor  of  Crishna,  author  of  the  Calpalatdvatdra.  The 
presumption  is  on  either  part  consistent  with  proximity  of  countrj':  Amard- 
vati  not  being  more  than  150  miles  distant  from  Nandlgrdma,  nor  more  than 
fiOO  from  Golagrdma.  It  is  on  one  side  made  probable  by  the  author's 
frequent  reference  to  a  commentary'  of  his  preceptor  Crishna,  which  in 
substance  corresponds  to  the  Calpalatdvatdra ;  but  the  title  differs,  for  he 
cites  the  Nacdncura.  On  the  other  side  it  is  to  be  remarked,  that  Crishna, 
father  of  the  Nrisinha,  who  wrote  the  J 'Vasand-vdrtica,  was  author  of  a 
a  treatise  on  Algebra,  which  is  mentioned  by  his  son,  as  before  observed. 

The  Manbratijana,  another  com  men  tar}'  on  the  Lildvati,  which  has  b^n 
used  in  the  progress  of  the  translation,  bears  no  date,  nor  any  indication' 
whatsoever  of  the  period  when  the  author  Ra'ma-Crishna  deta,  son  6f 
Sada'deva,  sumamed  Apadeva,  wrote.  '^ 

The  Ganila-caumudi,  on  the  LUdvati,  is  frequently  cited  by  the  modertf 

..,;;iiii 

■  G6Ig&m  of  the  maps,  in  Ut.  18<»  N.  long.  78°  E.  ^  ^„     ^^^^    ,,„^ 

*  A  great  commercial  town  in  Berdr.  _  ,  -%.■,,. 

^  .cj  ill  ti'jj.i  jb  STD  ^nti}ul3m 


xxviii  NOTES  AND  ILLUSTRATIONS. 

commentators,  and  in  particular  by  Su'rya-subi  and  Rangana't'ha  :  but 
has  not  been  recovered,  and  is  only  known  from  their  quotations. 

Of  the  numerous  commentaries  on  the  astronomical  portion  of  Bha'scara's 
Sidd'hdnta-sirSmani,  little  use  having  been  here  made,  either  for  settling  the 
text  of  the  algebraic  and  arithmetical  treatises  of  the  author,  or  for  interpreting 
particular  passages  of  them,  a  reference  to  two  commentaries  of  this  class, 
besides  those  of  Su'rya-suri  and  Gane's'a,  (which  have  not  been  recovered,) 
and  the  author's  own  annotations  and  the  interpretation  of  them  by 
Nrisinha  above  noticed,  may  suffice:  viz.  the  Gatiita-taiwa-chintmnani,  by 
Lacshmi'da'sa,  grandson  of  Ce'sava,  (probably  the  same  with  the  father  of 
Gane's'a  before  mentioned,)  and  son  of  Va'chespati,  dated  liQ3  Saca,  (A.D. 
1501);  and  the  Mdricha,  by  Muxis'wara,  surnamed  Vis'warupa,  grandson 
of  Balla'la,  and  son  of  Rangana't'ha,  who  was  compiler  of  a  work  dated 
1524  Haca  (A.D.  1602),  as  before  mentioned.  Muni's'wara  himself  is  the 
author  of  a  distinct  treatise  of  astronomy  entitled  Sidd'kdnta-sdrvabhau?>ia. 

Persian  versions  of  both  the  Lildvati  and  Vija-ganita  have  been  already 
noticed,  as  also  contributing  to  the  authentication  of  the  text.  The  first  by 
Faizi,  undertaken  by  the  command  of  the  Emperor  Acber,  was  executed  in 
the  32d  year  of  his  reign;  A.  H.  995,  A.D.  1587.  The  translation  of  the 
V'lja-ganita  is  later  by  half  a  century,  having  been  completed  by  Ata  Ullah 
Rashi'di,  in  the  8th  year  of  the  reign  of  Siia'h  Jeha'x  ;  A. II.  1044,  A.D. 
1634. 


B. 

ASTRONOMY  OF  BRAHMEGUPTA. 

Brahmegupta's  entire  work  comprises  twenty-one  lectures  or  chapters  ; 
of  which  the  ten  first  contain  an  astronomical  system,  consisting  (1st  and  2d) 
in  the  computation  of  mean  motions  and  true  places  of  the  planets ;  3d, 
solution  of  problems  concerning  time,  the  points  of  the  horizon,  and  the 
position  of  places;  4th  and  5th,  calculation  of  lunar  and  solar  eclipses;  6th, 
rising  and  setting  of  the  planets ;  7th,  position  of  the  moon's  cusps ;  8th, 
observation  of  altitudes  by  the  gnomon ;  9th,  conjunctions  of  the  planets ; 
and,  10th,  their  conjunction  with  stars.  The  next  ten  are  supplementary, 
including  five  chapters  of  problems  with  their  solutions :  and  the  twenty- 


BRAHMEGUPTA'S  ASTRONOMY.  xxix 

first  explains  the  principles  of  the  astronomical  system  in  a  compendious 
treatise  on  spherics,  treating  of  the  astronomical  sphere  and  its  circles,  the 
construction  of  sines,  the  rectification  of  the  apparent  planet  from  mean 
motions,  the  cause  of  lunar  and  solar  eclipses,  and  the  construction  of  the 
sirmillary  sphere. 

The  copy  of  the  scholia  and  text,  in  the  translator's  possession,  wants  the 
whole  of  the  6th,  7th,  and  8th  chapters,  and  exhibits  gaps  of  more  or  less 
extent  in  the  preceding  five ;  and  appears  to  have  been  transcribed  from  an 
exemplar  equally  defective.     From  the  middle  of  the  9th,  to  near  the  close  of 
the  15th  chapters,  is  an  uninterrupted  and  regular  series,  comprehending  a  very 
curious  chapter,  the  11th,  which  contains  a  revision  and  censure  of  earlier 
writers :  and  next  to  it  the  chapter  on  arithmetic  and  mensuration,  which  is 
the  1 2th  of  the  work.    It  is  followed  in  the  1 3th,  and  four  succeeding  chapters, 
by  solutions  of  problems  concerning  mean  and  true  motions  of  planets,  find- 
ing of  time,  place,  and  points  in  the  horizon ;  and  relative  to  other  matters, 
which  the  defect  of  the  two  last  of  five  chapters  renders  it  impracticable  to 
specify.     Next  comes,  (but  in  a  separate  form,  being  transcribed  from  a  diff^e- 
rent  exemplar,)  the  1 8th  chapter  on  Algebra.    The  two,  which  should  succeed, 
(and  one  of  which,  as  appears  from  a  reference  to  a  chapter  on  this  subject, 
treats  of  the  various  measures  of  time  under  the  several  denominations  of 
solar,  siderial,  lunar,  &c. ;  and  the  other,  from  like  references  to  it,  is  known 
to  treat  of  the  delineation  of  celestial  phoenomena  by  diagram,)  are  entirely- 
wanting,   the  remainder  of  the  copy    being  defective.     The   twenty-first 
chapter,  however,  which  is  last  in  the  author's  arrangement,  (as  the  corre- 
sponding book  on  spherics  of  Bhascaka's  Siddh&nta-siromaiii  is  in  his,) 
has  been  transposed  and  first  expounded  by  the  scholiast :  and  very  properly 
so,  since  its  subject  is  naturally  preliminary,  being  explanatory  of  the  prin- 
ciples of  astronomy.     It  stands  first  in  the  copy  under  consideration ;  and  is 
complete,  except  one  or  two  initial  couplets. 


xxx  NOTES  AND  ILLUSTRATIONS. 

c. 

BRAHMA-SIDD'HANTA,    TITLE    OF  BRAHMEGUPTA'S 

ASTRONOMY. 

The  passage  is  this:  "  TSn\ui.i6cta-graha-ganitam  mahatd  caUna  yat 
c'hili-bhutam,  abhid'hiyate  sphutan  tat  Jisn^u-suta  Brahmegupte'na." 

'  The  computation  of  planets,  taught  by  Brahma,  which  had  become  im- 
pei-fect  by  great  length  of  time,  is  propounded  correct  by  Brahmegupta  son 
of  Jishn'u.' 

The  beginning  of  PRfr'nuDACA's  commentary  on  the  Brahma-sidd'hanta, 
where  the  three  initial  couplets  of  the  text  are  expounded,  being  deficient, 
the  quotation  cannot  at  present  be  brought  to  the  test  of  collation.  But  the 
title  is  still  more  expressly  given  near  the  close  of  the  eleventh  chapter, 
(§  59)  "  Brdhme  sphuta-sidd'hanti  ravindu-bhd  y6gam,  &c." 

And  again,  (§  60  "  Chandra-rcevigrahanindu-cJihdyadishu  sarvada  yatb 
Brahmt,  drig-ganitaicyam  bhavati,  sphut'd-sidd'hantas  tat 6  Brahmah." 
*  As  observation  and  computation  always  agree  in  respect  of  lunar  and  solar 
eclipses,  moon's  shadow  (i.  e.  altitude)  and  other  particulars,  according  to 
the  Brahma,  therefore  is  the  Brahma  a  correct  system,  (sphuia-siddlianta) .^ 

It  appears  from  the  purport  of  these  several  passages  compared,  that 
Brahmegupta's  treatise  is  an  emendation  of  an  earlier  system,  (bearing  the 
same  name  of  Brahma-sidd'hdnta,  or  an  equivalent  title,  as  Pitdmaha- 
sidd'hanta,  or  adjectively  Paitdmaha,)  which  had  ceased  to  agree  with 
the  phoenomena,  and  into  which  requisite  corrections  were  therefore  intio- 
duced  by  him  to  reconcile  computation  and  observation  ;  and  he  entitled  his 
amended  treatise  '  Correct  Brahma-sidd'hdnta.'  That  earlier  treatise  is  con- 
sidered to  be  the  identical  one  which  is  introduced  into  the  Vishnu-dlierm6t- 
tara  purdna,  and  from  which  parallel  passages  are  accordingly  cited  by  the 
scholiasts  of  Bha'scara.  (See  following  note.)  It  is  no  doubt  the  same 
which  is  noticed  by  Vara'hamihira  under  the  title  oi  Paitdmaha  ^nd  Brahma 
siddhanta.  Couplets,  which  are  cited  by  his  commentator  Bh at'totpala from 
the  Brahma-siddlidnta,  are  found  in  Brahmegupta's  work.  But  whether 
the  original  or  the  amended  treatise  be  the  one  to  which  the  scholiast  re- 
ferred, is  nevertheless  a  disputable  point,  as  the  couplets  in  question  may  be 
among  passages  which  Brahmegupta  retained  unaltered. 


NOTES  AND  ILLUSTRATIONS.  xxxi 

D. 

VERIFICATION   OF  THE    TEXT  OF  BRAHMEGUPTA'S 
TREATISE  OF  ASTRONOMY. 

A  PASSAGE,  referring  the  commencement  of  astronomical  periods  and  of 
planetary  revolutions,  to  the  supposed  instant  of  the  creation,  is  quoted  from 
Brahmegupta,  with  a  parallel  passage  of  another  Brahma  siddhanta 
(comprehended  in  the  Vishnu-dhermottara-purdna)  in  a  compilation  by 
MunisVara  one  of  Bha'scara's  glossators.'  It  is  verified  as  the  4th  couplet 
of  Braumegupta's  first  chapter  (upon  mean  motions)  in  the  translator's  copy. 

Seven  couplets,  specifying  the  mean  motions  of  the  planets'  nodes  and 
apogees,  are  quoted  after  the  parallel  passage  of  the  other  Brahma  sidd'hdnta, 
by  the  same  scholiast  of  Bha'scara,  as  the  text  of  Brahmegupta  :  and  they 
are  found  in  the  same  order  from  the  15th  to  the  21st  in  the  first  chapter  of 
his  work  in  the  copy  above  mentioned. 

This  commentator,  among  many  other  corresponding  passages  noticed  by 
him  on  various  occasions,  has  quoted  one  from  the  same  Bralnna  sidd'hdnta  of 
the  Kishriu-dharmottara  concerning  the  orbits  of  the  planets  deduced  from  the 
magnitude  of  the  sky  computed  there,  as  it  also  is  by  Brahmegupta  (ch.  21, 
§9),  but  in  other  words,  at  a  circumference  of  1871206y200000000  yojanas : 
he  goes  on  to  quote  the  subsequent  couplet  of  Brahmegupta  declaring  that 
planets  travel  an  equal  measured  distance  in  their  orbits  in  equal  times  :  and 
then  cites  his  scholiast  (ticacdra)  Chaturve'da'cha'rya, 

The  text  of  Brahmegupta  (ch.  1,  §21)  specifying  the  diurnal  revolutions 
of  the  siderial  sphere,  or  number  of  siderial  days  in  a  calpa,  with  the  corre-, 
spontlent  one  of  the  Paitdmaha  sidd'hdnta  in  the  Vishiu-dherrndttara,  is  ano- 
ther of  the  quotations  of  the  same  writer  in  his  commentary  on  Bha'scara. 

A  passage  relating  to  oval  epicycles,"  cited  by  the  same  author  in  another 
place,  is  also  verified  in  the  2d  chapter  (in  the  rectification  of  a  planet's  place). 

A  number  of  couplets  on  the  subject  of  eclipses'  is  cited  by  Lacshmida'sa', 
a  commentator  of  Bha'scara.  They  are  found  in  the  5th  chapter  (on 
eclipses)  §  10  and  24  ;  and  in  a  section  of  the  2 1st  (on  the  cause  of  eclipses) 
§  37  to  46,  in  the  copy  in  question. 

Several  couplets,  relating  to  the  positions  of  the  constellations  and  to  the 

'  As.  Res.  12,  p.  232.  «  Ibid.  12,  p.  236.  *  Ibid.  12,  p.  2«. 


xxxii  NOTES  AND  ILLUSTRATIONS. 

longitudes  and  latitudes  of  principal  fixt  stars,  are  cited  from  Bkahmeoupta 
in  numerous  compilations,  and  specifically  in  the  commentaries  on  the  Surya- 
sidd'hanta  and  Sidd^hanta-sirdmani.'^  They  are  all  found  correct  in  the  10th 
chapter,  on  the  conjunctions  of  planets  with  fixt  stars. 

A  quotation  hy  Gan js's'a  on  the  LHdvati  (A.  D.  1545)  describing  the  attain- 
ments of  a  true  mathematician,*  occurs  with  exactness  as  the  first  couplet  of 
the  12th  chapter,  on  arithmetic;  and  one  adduced  by  Bua'scara  himself,  in 
his  arithmetical  treatise  (§  190),  giving  a  rule  for  finding  the  diagonal  of  a 
trapezium,'  is  precisely  the  28th  of  the  same  chapter. 

A  very  important  passage,  noticed  by  Bha'scara  in  his  notes  on  his 
Sidd'hanta-siromani,  and  alluded  to  in  his  text,  and  fully  quoted  by  his  com- 
mentator in  the  Markka,  relative  to  the  rectification  of  a  planet's  true  place 
from  the  mean  motions,*  is  found  in  the  21st  chapter,  §  27.  Bha'scara  has, 
on  that  occasion,  alluded  to  the  scholiast,  who  is  accordingly  quoted  byname 
in  the  commentary  of  Lacshmi'da'sa  (A.  D.  1501)  :  and  here  again  the  cor- 
respondence is  exact. 

The  identity  of  the  text  as  Brahmegupta's,  and  of  the  gloss  as  his  scho- 
liast's, being  (by  these  and  many  other  instances,  which  have  been  collated,) 
satisfactorily  established  ;  as  the  genuineness  of  the  text  is  by  numerous  quo- 
tations from  the  Brahma-siddhanta  (without  the  author's  name)  in  the  more 
ancient  commentary  of  Bhat'totpala  (A.  D.  968)  on  the  works  of  Vara'ha- 
wiHiRA,  which  also  have  been  verified  in  the  mutilated  copy  of  the  Brahma- 
sidd'hanta  under  consideration ;  the  next  step  was  the  exainination  of  the 
detached  copy  of  a  commentary  on  the  18th  chapter,  upon  Algebra,  Avhich  is 
terminated  by  a  colophon  so  describing  it,  and  specifying  the  title  of  the  entire 
book  Brahma-sidd'' hdnta,  and  the  name  of  its  author  Brahmegupta. 

For  this  purpose  materials  are  happily  presented  in  the  scholiast's  enume- 
ration, at  the  close  of  the  chapter  on  arithmetic,  of  the  topics  treated  by  his 
author  in  the  chapter  on  Algebra,  entitled  Cutiaca :'  in  a  general  reference 
to  the  author's  algorithm  of  unknown  quantities,  affirmative  and  negative 
terms,  cipher  and  surd  roots,  in  the  same  chapter  ;*  and  the  same  scholiast's 
quotations  of  the  initial  words  of  four  rules;  one  of  them  relative  to  surd 
roots  ;^  the  other  three  regarding  the  resolution  of  quadratic  equations  ;*  aa 

'  >  As.  Res.  9.  Essay  6.  2  Lil.  ch.  11.  *"  Lit.  §  190. 

♦  As.  Res.  12,  239.  '  Arithra.  of  Brahm.  §  66.  •  Ibid.  §  13. 

'  Ibid,  §  39.  •  Ibid.  §  15  &  18. 


NOTES  AND  ILLUSTRATIONS.  xxxiii 

also  in  the  references  of  the  schoHast  of  the  Algebraic  treatise  to  passages  in 
the  astronomical  part  of  his  author's  work.* 

The  quotations  have  been  verified;  and  they  exactly  agree  with  the  rule 
concerning  surds  (§  26)  and  the  three  rules  which  compose  the  section  relating 
to  quadratic  equations  (§  32 — 34) ;  and  with  the  rule  in  the  chapter  on  the 
solution  of  astronomical  problems  concerning  mean  motions  (ch.  13,  §  22) : 
and  this  verification  and  the  agreement  of  the  more  general  references 
demonstrate  the  identity  of  this  treatise  of  Algebra,  consonantly  to  its  colo- 
phon, as  Brahmegupta's  Algebra  entitled  Cuttaca  and  a  part  of  his 
Brahma-sidd'hdnta. 


E. 

CHRONOLOGY  OF  ASTRONOMICAL  AUTHORITIES  ACCORD- 
ING TO  ASTRONOMERS  OF  UJJAYANL 

The  names  of  astronomical  writers  with  their  dates,  as  furnished  by  the 
astronomers  of  Ujjayani  who  were  consulted  by  Dr.  William  Hunter  so- 
journing there  with  a  British  embassy,  are  the  following: 


Vaka'ha-mihira 

122  Saca 

[A.  D.    200-lX 

Another  Vara'ha-mihira 

427 

[A.  D.    505-6] 

Brahmegupta 

550 

[A.  D.    628-9] 

Munja'la 

854. 

[A.D.    932-3] 

Bhat'totpala 

890 

[A.  D.  1068-9] 

Swe't6tpala 

939 

[A.  D.  1017-8] 

Varun'a-bhatt'a 

962 

[A.  D.  1040-1] 

Bh6ja-raja 

964 

[A.  D.  1042-3] 

Bha'scara 

1072 

[A.  D.  1 150-1] 

Calyana-chandra 

1101 

[A.D.  11 79-80] 

The  grounds,  on  which  this  chronology  proceeds,  are  unexplained  in  the 
note  which  Dr.  Hunter  preserved  of  the  communication.  But  means  exist 
for  verifying  two  of  the  dates  specified  and  corroborating  others. 

Tliedate,  assigned  to  Bha'scara,  is  precisely  that  of  his  5i</rf'A««/«-i/>o»2fl!«'i, 
plainly  concluded  from  a  passage  of  it,  in  which  he  declares,  that  it  was 


•  Alg.  of  Brahm.  §  S6  (Rule  55). 
f 


I 


xxxiv  NOTES  AND  Ii>tUSJRATIONS. 

completed  by  him,  being  thirty-six  years  of  age  ;  and  that  his  birth  was  in 
1036  Saca. 

Rajd  Bh6ja-deva,  or  Bh6ja-iia'ja,  is  placed  in  this  list  of  Hindu  astrono- 
mers apparently  on  account  of  his  name  being  affixed  as  that  of  the  author, 
to  an  astrological  treatise  on  the  calendar,  which  bears  the  title  of  Rdja- 
m&rtanda,  and  which  was  composed  probably  at  his  court  and  by  astrologers 
in  his  service.  It  contains  no  date  ;  or  at  least  none  is  found  in  the  copy 
which  has  been  inspected.  But  the  age  assigned  to  the  prince  is  not  incon- 
sistent with  Indian  History :  and  is  supported  by  the  colophon  of  a  poem 
entitled  Subh6shita  ratna-sandoha,  composed  by  a  Jia/wa  sectary  named  Amita- 
GATi  who  has  given  the  date  of  his  poem  in  1050  oi  Vicramaditya,  in  the 
reign  of  Munja.  Now  Munja  was  uncle  and  predecessor  of  Bh6ja-ka'ja, 
being  regent,  with  the  title  of  sovereign,  during  his  nephew's  minority  :  and 
this  date,  which  answers  to  A.  D.  993-4,  is  entirely  consistent  with  that  given 
by  the  astronomers  of  UJjayani,  viz.  964  Saca  corresponding  to  A.  D.  1042-3 : 
fpr  the  reign  of  Bk6j  a-de'va  was  long :  extending,  at  the  lowest  computation, 
to  half  a  centur}',  and  reaching,  according  to  an  extravagant  reckoning,  to  the 
round  number  of  an  hundred  years. 

The  historical  notices  of  this  King  of  Dhdrd  *  are  examined  by  Major 
WiLFORD  and  Mr.  Bentley  in  the  9th  and  8th  volumes  of  Asiatic  Researches  r 
and  they  refer  him  to  the  tenth  century  of  the  Christian  era ;  the  one  making 
him  ascend  the  throne  in  A.  D.  982  ;  the  other,  in  A.  D.  913.  The  former, 
which  takes  his  reign  at  an  entire  century,  including  of  course  his  minority, 
or  the  period  of  the  administration,  reign,  or  regency,  of  his  uncle  Munja,  is 
compatible  with  the  date  of  Amitagati's  poem  (A.  D.  993)  and  with  that  of 
the  Rdja-ynartarida  or  other  astrological  and  astronomical  works  ascribed  to 
him  (A.  D.  1042)  according  to  the  chronology  of  the  astronomers  of  Ujjayani. 

The  age,  assigned  to  Buahmegupta,  is  corroborated  by  the  arguments 
adduced  in  the  text.  That,  given  to  Munja'la,  is  consistent  with  the  quota- 
tion of  him  as  at  the  head  of  a  tribe  of  authors,  by  Bua'scara  at  the  distance 
of  two  centuries.  The  period  allotted  to  Vara'hamiuira,  that  is,  to  the 
second  and  most  celebrated  of  the  name,  also  admits  corroboration.  This 
point,  however,  being  specially  important,  to  the  history  of  Indian  astronomy, 
and  collaterally  to  that  of  the  Hindu  Algebra,  deserves  and  will  receive  a 
full  and  distinct  consideration. 

'  The  modern  Dhar.    Wilford.  As.  Res. 


NOTES  AND  ILLUSTRATIONS.  xxxv 


F.  -^ 

AGE  OF  BRAHMEGUPTA  INFERRED  FROM  ASTRONOMI- 
CAL DATA. 

The  star  Chitra,  which  unquestionably  is  Spica  Virginis,^  was  referred  by 
BuAHMEGUPTA  to  the  103d  degree  counted  from  its  origin  to  the  inter- 
section of  the  star's  circle  of  declination  j*'  whence  the  star's  right  ascension  is 
deduced  182°  45'.  Its  actual  right  ascension  in  A.  D.  1800  was  198°  40'  2".* 
The  difference,  \5°  55'  2",  is  the  quantity,  by  which  the  beginning  of  the  first 
zodiacal  asterism  and  lunar  mansion,  Aswini,  as  inferible  from  the  position  of 
the  star  Chitra,  has  receded  from  the  equinox:  and  it  indicates  the  lapse  of 
1216  years  (to  A.  D.  1800,)  since  that  point  coincided  with  the  equinox;  the 
annual  precession  of  the  star  being  reckoned  at  47',  H-f 

The  star  Revati,  which  appears  to  be  ^  Piscium,'  had  no  longitude,  accord- 
ing to  the  same  author,  being  situated  precisely  at  the  close  of  the  asterism 
and  commencement  of  the  following  one,  Aswini,  Avithout  latitude  or  decli- 
nation, exactly  in  the  equinoctial  point.  Its  actual  right  ascension  in 
1800  was  15°  49'  15".*  This,  which  is  the  quantity  by  which  the  origin  of 
the  Indian  ecliptic,  as  inferible  from  the  position  of  the  star  RSvatt,  has  re- 
ceded from  the  equinox,  indicates  a  period  of  1221  years,  elapsed  to  the  end 
of  the  eighteenth  century ;  the  annual  precession  for  that  star  being  46",  63.^ 

The  mean  of  the  two  is  1218-1^  years;  which,  taken  from  1800,  leave  581 
or  582  of  the  Christian  era.  Brahmegupta  then  appears  to  have  observed 
and  written  towards  the  close  of  the  sixth,  or  the  beginning  of  the  following 
century;  for,  as  the  Hindu  astronomers  seem  not  to  have  been  very  accurate 
observers,  the  belief  of  his  having  lived  and  published  in  the  seventh 
century,  about  A.  D.  628,  which  answers  to  550  Saca,  the  date  assigned 
to  him  by  the  astronomers  of  Ujjayani,  is  not  inconsistent  with  the  position, 
that  the  vernal  equinox  did  not  sensibly  to  his  view  deviate  from  the  begin- 

•  As.  Res.  vol.9,  p.  339.  (8vo.) 

*  Ibid.  9,  327,  (8vo.),  and  12,  p.  240. 

•  Zach's  Tables  for  1800  deduced  from  Ma»kelyne'«  Catalogue. 

t  Maskelyne's  Caulogue:  the  mean  precession  of  the  equinoctial  points  being  recijoncd  50",  3, 

*  As.  Reg.  9, p.  346.  (8vo.)  «  Zachs Tables.  '  Zach's  Tables.  .^  , 

f2 


xxxvi  NOTES  AND  ILLUSTRATIONS. 

ning  of  Aries  or  MSsha,  as  determined  by  him  from   the  star  Rkvati 
(^  Piscium)  which  he  places  at  that  point. 

The  same  author  assigns  to  Agastya  or  Canopus  a  distance  of  87°,  and  to 
Lubd'haca  or  Sirius  86°,  from  the  beginning  of  Misha.  From  these  positions 
a  mean  of  1280  years  is  deducible. 

The  passage  in  which  this  author  denies  the  precession  of  the  colures,  as 
well  as  the  comment  of  his  scholiast  on  it,  being  material  to  the  present 
argument,  they  are  here  subjoined  in  a  literal  version. 

'  The  very  fewest  hours  of  night  occur  at  the  end  of  Mit'huna;  and  the 
seasons  are  governed  by  the  sun's  motion.  Therefore  the  pair  of  solstices 
appears  to  be  stationary,  by  the  evidence  of  a  pair  of  eyes.'* 

Scholia:  '  What  is  said  by  Vishnu  Chandra  at  the  beginning  of  the 
chapter  on  thcyuga  of  the  solstice:  ("  Its  revolutions  through  the  asterisms 
are  here  [in  the  calpd]  a  hundred  and  eighty-nine  thousand,  four  hundred  and 
eleven.  This  is  termed  a  yuga  of  the  solstice,  as  of  old  admitted  by  Brahma, 
AucA,  and  the  rest.")  is  wrong:  for  the  very  fewest  hours  of  night  to  us 
occur  when  the  sun's  place  is  at  the  end  of  Mit'huna  [Gemini];  and  of 
course  the  very  utmost  hours  of  day  are  at  the  same  period.  From  that  limi- 
tary point,  the  sun's  progress  regulates  the  seasons;  namely,  the  cold  season 
(sisira)  and  the  rest,  comprising  two  months  each,  reckoned  from  Macara 
[Capricorn].  Therefore  what  has  been  said  concerning  the  motion  of  the 
limitary  point  is  wrong,  being  contradicted  by  actual  observation  of  days 
and  nights. 

'  The  objection,  however,  is  not  valid:  for  now  the  greatest  decrease  and 
increase  of  night  and  day  do  not  happen  when  the  sun's  place  is  at  the  end  of 
Mit'huna:  and  passages  are  remembered,  expressing  "  The  southern  road  of 
the  sun  was  from  the  middle  of  Aslesha;  and  the  northern  one  at  the  be- 
ginning of  Dhanishfhaf"  and  others  [of  like  import].  But  all  this  only 
proves,  that  there  is  a  motion;  not  that  the  solstice  has  made  many  revolu- 
tions through  the  asterisms.'' 

It  was  hinted  at  the  beginning  of  this  note,  tliat  Brahmegupta's  longi- 
tude (dhruvaca)  of  a  star  is  the  arc  of  the  ecliptic  intercepted  by  the  star's 
circle  of  declination,  and  counted  from  the  origin  of  the  ecliptic  at  the  be- 

'  Brahma-sidd'Mnta,  1 1 ,  §  54. 

*This  quotation  is  from  Vara'ha-miuira's  sanhitd,  cb,  3,  §  1  and  2. 

*  Prit'hu'daca  swami  ciiaturveda  on  Brahm. 


i 


AGE  OF  BRAHMEGUPTA.  xxxvii 

ginning  of  Meshd;  as  his  latitude  (vicshepa)  of  a  star  is  the  star's  distance 
on  a  circle  of  declination  from  its  point  of  intersection  with  the  ecliptic.  In 
short,  he,  like  other  Hindu  astronomers,  counts  longitude  and  latitude  of  stars 
by  the  intersection  of  circles  of  declination  with  the  ecliptic.  The  subject 
had  been  before  noticed.*  To  make  it  more  clear,  an  instance  may  be  taken: 
and  that  of  the  scholiast's  computation  of  the  zenith  distance  and  meridian 
altitude  of  Canopus  for  the  latitude  of  Canyacubja  (Canouj)  may  serve  as  an 
apposite  example. 

From  the  vicshepa  of  the  star  Agastya,  77°,  he  subtracts  the  declination  of 
the  intersected  point  of  the  ecliptic  23°  58';  to  the  remainder,  which  is  the 
declination  of  the  star,  53°  2',  he  adds  the  latitude  of  the  place  26°  S5':,  the 
sum,  79°  37',  is  the  zenith  distance;  and  its  complement  to  ninety  degrees, 
10"  23',  is  the  meridian  altitude  of  the  star.'^ 

The  annual  variation  of  the  star  in  declination,  l",  7,  is  too  small  to  draw 
any  inference  as  to  the  age  of  the  scholiast  from  the  declination  here  stated. 
More  especially  as  it  is  taken  from  data  furnished  by  his  author;  and  as  he 
appears  to  have  been,  like  most  of  the  Hindu  astronomers,  no  very  accurate 
observer;  the  latitude  assigned  by  him  to  the  city,  in  which  he  dwelt,  being 
no  less  than  half  a  degree  wrong:  for  the  ruins  of  the  city  o^  Canouj  are  in 
27°  5'  N. 


G. 

ARYABHAffA'S  DOCTRINE. 

Aryabhatta  was  author  of  the  Aryashiasata  (800  couplets)  and  Dasagi- 
tica  (ten  stanzas),  known  by  the  numerous  quotations  of  Brahmegupta, 
Bhat't6tpala,  and  others,  who  cite  both  under  these  respective  titles.  The 
laghu  Arya-sidd'hanta,  as  a  work  of  the  same  author,  and,  perhaps,  one  of 
those  above-mentioned,  is  several  times  quoted  by  Bha'scara's  commentator 
MuNi's'wARA.  He  likewise  treated  of  Algebra,  &c.  under  the  distinct  heads 
of  Cuitaca,  a  problem  serving  for  the  resolution  of  indeterminate  ones,  and 
Vija  principle  of  computation,  or  analysis  in  general. — LU.  c.  1 1. 

■  As.  Res.  9,  p.  327-  (8vo.),  and  12,  p.  240  ;   (4to.) 
^  Peit'iiu'daca  swAiif  on  Brahm.  ch.  10,  i  35. 


xxxvHi  NOTES  AND  ILLUSTRATIONS. 

From  the  quotations  of  writers  on  astronomy,  and  particularly  of  Brahme- 
CUPTA,  who  in  many  instances  cites  Aryabhat't'a  to  controvert  his  positions, 
(and  is  in  general  contradicted  in  his  censure  by  his  own  scholiast  PriVhu- 
DACA,  cither  correcting  his  quotations,  or  vindicating  the  doctrine  of  the 
earlier  author),  it  appears,  that  Aryabhatta  affirmed  the  diurnal  revolution 
of  the  earth  on  its  axis;  and  that  he  accounted  for  it  by  a  wind  or  current  of 
aerial  fluid,  the  extent  of  which,  accoitiing  to  the  orbit  assigned  to  it  by  him, 
corresponds  to  an  elevation  of  little  more  than  a  hundred  miles  from  the  sur- 
face of  the  earth ;  that  he  possessed  the  true  theory  of  the  causes  of  lunar  and 
solar  eclipses,  and  disregarded  the  imaginary  dark  planets  of  the  mythologists 
and  astrologers;  affirming  the  moon  and  primary  planets  (and  even  the  stars) 
to  be  essentially  dark,  and  only  illumined  by  the  sun :  that  he  noticed  the 
motion  of  the  solstitial  and  equinoctial  points,  but  restricted  it  to  a  regulai' 
oscillation,  of  which  he  assigned  the  limit  and  the  period  :  that  he  ascribed 
to  the  epicycles,  by  which  the  motion  of  a  planet  is  represented,  a  form 
varying  from  the  circle  and  nearly  elliptic :  that  he  recognised  a  motion  of 
the  nodes  and  apsides  of  all  the  primary  planets,  as  well  as  of  the  moon; 
though  in  this  instance,  as  in  some  others,  his  censurer  imputes  to  him 
variance  of  doctrine. 

The  magnitude  of  the  earth,  and  extent  of  the  encompassing  wind,  is 
among  the  instances  wherein  he  is  reproached  by  Brahmegupta  with  ver- 
satility, as  not  having  adhered  to  the  same  position  throughout  his  writings; 
but  he  is  vindicated  on  this,  as  on  most  occasions,  by  the  scholiast  of  his  cen- 
surer. Particulars  of  this  question,  leading  to  rather  curious  matter,  deserve 
notice. 

Aryabhatt'a's  text  specifies  the  earth's  diameter,  \050  yojanas ;  and  the 
orbit  or  circumference  of  the  earth's  wind  [spiritus  vector]  3393  yojanas; 
which,  as  the  scholiast  rightly  argues,  is  no  discrepancy.  The  diameter  of 
this  orbit,  according  to  the  remark  of  Brahmegupta,  is  1080. 

On  this,  it  is  to  be  in  the  first  place  observed,  that  the  proportion  of  the 
circumference  to  the  diameter  of  a  circle,  here  employed,  is  that  of  22  to  7; 
which,  not  being  the  same  which  is  given  by  Brahmegupta 's  rule,  (Aritlmit 
§  40,)  must  be  presumed  to  be  that,  which  Aryabhat'ta  taught.  Applying 
it  to  the  earth's  diameter  as  by  him  assigned,  viz.  1050,  the  circumference  of 
the  earth  is  3300;  which  evidently  constitutes  the  dimensions  by  him  in- 


ARYABHATTA'S  DOCTRINE.  xxxix 

tended  :  and  that  number  is  accordingly  stated  by  a  commentator  of  Bha's- 
CARA.     See  Gaii.  on  Lil.  §  4. 

This  approximation  to  the  proportion  of  the  diameter  of  a  circle  to  its 
periphery,  is  nearer  than  that  which  both  Brahmegupta  and  Sri'd'hara, 
though  later  writers,  teach  in  their  mensuration,  and  which  is  employed  in 
the  Surya-siddhdnta;  namely,  one  to  the  square-root  often.  It  is  adopted 
by  Bha'scara,  who  adds,  apparently  from  some  other  authority,  the  still 
nearer  approximation  of  1250  to  3927- — {Lil.  §  201.) 

Aryabhat't'a  appears,  however,  to  have  also  made  use  of  the  ratio  which 
afterwards  contented  both  Brahmegupta  and  Sri'd'hara;  for  his  rule  ad^ 
duced  by  Gan'e's'a  (Zz/.  §  207)  for  finding  the  arc  from  the  chord  and  versed 
sine,  is  clearly  founded  on  the  proportion  of  the  diameter  to  the  periphery, 
as  one  to  the  square  root  of  ten:  as  will  be  evident,  if  the  semicircle  be  com- 
puted by  that  rule:  for  it  comes  out  the  square  root  of'-/,  the  diameter 
being  1. 

A  more  favourable  notion  of  his  proficiency  in  geometry,  a  science,  how- 
ever, much  less  cultivated  by  the  Hindus  than  Algebra,  may  be  received  from 
his  acquaintance  with  the  theorem  containing  the  fundamental  property  of 
the  circle,  which  is  cited  by  PkiVhu'daca. — {Bi^ahm.  12,  §21.) 

The  number  of  3300  ybjanas  for  the  circumference  of  the  earth,  or  Q\ 
ybjanas  for  a  degree  of  a  great  circle,  is  not  very  wide  of  the  truth,  and  is, 
indeed,  a  very  near  approach,  if  the  ydjana,  which  contains  four  crSsas,  be 
rightly  inferred  from  the  modern  computed  crosa  found  to  be  1,  9  B.  M.' 
For,  at  that  rate  of  7,  6  miles  to  a  yojana,  the  earth's  circumference  would  be 
25080  B.  miles. 

Tlie  difference  between  the  diameter  of  the  earth,  and  that  of  its  air  (vayu), 
by  which  term  Aryabhat'ta  seems  to  intend  a  current  of  wind  whirling  as  a 
vortex,  and  causing  the  earth's  revolution  on  its  axis,  leaves  15  yojanas,  or 
1 14  miles,  for  the  limit  of  elevation  of  this  atmospheric  current. 

■  As.  Res.  5. 105.  (Svo.) 


jd  NOTES  AND  ILLUSTRATIONS. 

H. 

SCANTINESS  OF  THE  ADDITIONS  BV  LATER  WRITERS  ON 

ALGEBRA. 

i  The  observation  in  the  text  on  the  scantiness  of  the  improvements  or  ad- 
flitions  made  to  the  Algebra  of  the  Hindus  in  a  long  period  of  years  after 
Aeyabhatta  probably,  and  after  Brahmegupta  certainly,  is  extended  to 
authors  whose  works  are  now  lost,  on  the  faith  of  quotations  from  them. 
Srid'hara's  rule,  which  is  cited  by  Bha'scaua  {Vij.-gaii.  §  131)  concerning 
quadratics,  is  the  same  in  substance  with  one  of  Brahmegupta's  (Ch.  18. 
§32 — 33).  Padmana'bha,  indeed, appears  from  the  quotation  from  his  treatise 
{V'y.-gan.  §  142.)  to  have  been  aware  of  quadratic  equations  aifordiug  two 
roots;  which  Brahmegupta  has  not  noticed;  and  this  is  a  material  acces- 
sion which  the  science  received.  There  remains  an  uncertainty  respecting 
the  author,  from  whom  Bha'scara  has  taken  the  resolution  of  equations  of 
tlie  third  and  fourth  degrees  in  their  simple  and  unaffected  cases. 

The  only  names  of  Algebraists,  who  preceded  Bha'scara,  to  be  added  to 
those  already  mentioned,  are  1st  aw  earlier  writer  of  the  same  name  (Bha's- 
cara) who  was  at  the  head  of  the  commentators  of  Aryabhatt'a  ;  and  2d, 
the  elder  scholiast  of  the  Brahma-sidd'h&nta,  named  Bhatta  Balabhadra. 
Both  are  repeatedly  cited  by  the  successor  of  the  latter  in  the  same  task  of 
exposition,  PriVhu'daca  Swa'mi;  who  was  himself  anterior  to  the  author  of 
the  Siromani;  being  more  than  once  quoted  by  him.  As  neither  of  those 
earlier  commentators  is  named  by  the  younger  Bha'scara;  nor  any  intima- 
tion given  of  his  having  consulted  and  employed  other  treatises  besides  the 
three  specified  by  him,  in  the  compilation  of  the  Vija-ganita,  it  is  presumable, 
that  the  few  additions,  which  a  comparison  with  the  Cuttaca  of  Brahme- 
gupta exhibits,  are  properly  ascribable  either  to  Sri'd'hara  or  to  Padma- 
va'bha  :  most  likely  to  the  latter ;  as  he  is  cited  for  one  such  addition  ;'  and 
as  Srid'hara's  treatise  of  arithmetic  and  mensuration,  which  is  extant,  is 
not  seemingly  the  work  of  an  author  improving  on  the  labours  of  those 
who  went  before  him.*  The  corrections  and  improvements  introduced  by 
Bha'scara  himself,  and  of  which  he  carefully  apprizes  his  readers,'  are  not 
very  numerous,  nor  in  general  important.* 

•  Vy-gan.  §  142.  »  Lil.  §  147.     Brahm.  12,  §  21  and  40.     Gan.  Sar.  §  126. 
'  ^'U'-gci'  before  §  44,  and  after  §  57.  also  Cb.  1,  towards  the  end;  and  Ch.  5.  §  142. 

*  Unless  Lil.  §  170  and  190. 


NOTES  AND  ILLUSTRATIONS.  xli 


I. 

AGE  OF  ARYABHATTA. 

LENDER  the  Abbasside  Khalifs  Almansu'k  and  Almamux,  in  the  middle 
of  the  eighth  and  beginning  of  the  ninth  centuries  of  the  Christian  era,  tlie 
Arabs  became  conversant  with  the  Indian  astronomy.  It  was  at  that  period, 
as  may  be  presumed,  that  they  obtained  information  of  the  existence  and 
currency  of  three  astronomical  systems  among  the  Indians ;'  one  of  which 
bore  the  name  of  Aryabhatt'a,  or,  as  written  in  Arabic. characters,  Arja- 
BAHAR,*  (perhaps  intended  for  Akjabhar)  which  is  as  near  an  approxima- 
tion as  the  difference  of  characters  can  be  expected  to  exhibit.  This  then 
unquestionably  was  the  system  of  the  astronomer  whose  age  is  now  to  be 
investigated ;  and  who  is  in  a  thousand  places  cited  by  Hindu  writers  on 
Astronomy,  as  author  of  a  system  and  founder  of  a  sect  in  this  science.  It 
is  inferred  from  the  acquaintance  of  the  Arabs  with  the  astronomical  attain- 
ments of  the  Hindus,  at  that  time,  when  the  court  of  the  Khalif  drew  the 
visit  of  a  Hindu  astrologer  and  mathematician,  and  when  the  Indian  deter- 
mination of  the  mean  motions  of  the  planets  was  made  the  basis  of  astrono- 
mical tables  compiled  by  order  of  the  Khalifs,  '  for  a  guide  in  matters  per- 
taining to  the  stars,'  and  when  Indian  treatises  on  the  science  of  numbers 
were  put  in  an  Arabic  dress  j  adverting  also  to  the  difficulty  of  obtaining 
further  insight  into  the  Indian  sciences,  which  the  author  of  the  Tdrikhul 
hukmd  complains  of,  assigning  for  the  cause  the  distance  of  countries,  and 
the  various  impediments  to  intercourse :  it  is  inferred,  we  say,  from  these, 
joined  to  other  considerations,  that  the  period  in  question  was  that  in  which 
the  name  of  Aryabhatta  was  introduced  to  the  knowledge  of  the  Arabs. 
This,  as  a  first  step  in  inquiring  the  antiquity  of  this  author,  ascertains  his 
celebrity  as  an  astronomical  authority  above  a  thousand  years  ago. 

He  is  repeatedly  named  by  Hindu  authors  of  a  still  earlier  date:  particu- 
larly by  Brahmegupta,  in  the  first  part  of  the  seventh  century  of  the  Chris- 
tian era.  He  had  been  copied  by  writers  whom  Brahmegupta  cites. 
Vara'ha-mihira  has  allusions  to  him,  or  employs  his  astronomical  determi- 

'  Tar'Mu'l  huhma,  or  Bibl.  Arab.  Phil,  quoted  by  Casiri  :  Bibl.  Arab.  Hisp.  426.  See  below, 
Note  M.  :   f  1    ,  1 

*  CossALi's  Argebahr  is  a  misprint  (Orig.  &c.  dell'  Alg.  i.  207).  Casiri  gives,  as  in  the  Arabic, 
Argebahr:  \^bicb,  in  the  orthography  here  followed,  is  Arjabahr. 

or 

3 


atlii  NOTES  AND  ILLUSTRATIONS. 

nations  in  an  astrological  work  at  the  beginning  of  the  sixth  centurj'.     These 
facts  will  be  further  weighed  upon  as  wc  proceed. 

For  determining  Aryabhatta's  age  with  the  greater  precision  of  astro- 
nomical chronology,  grounds  are  presented,  at  the  first  view  promising,  but 
on  examination  insufficient. 

In  the  investigation  of  the  question  upon  astronomical  grounds,  recourse 
was  in  the  first  place  had  to  his  doctrine  concerning  the  precession  of  the 
equinoxes.  As  quoted  by  Munis'wara,  a  scholiast  of  Bha'scaua,  he  main- 
tained an  oscillation  of  the  equinoctial  points  to  twenty-four  degrees  on 
either  sidej  and  he  reckoned  578159  such  librations  in  a  calpa.^  From  ano- 
ther passage  cited  by  BnATT6TPAi.A  on  Vaba'ha-mihira,*  his  position  of  the 
mean  equinoxes  was  the  beginning  of  Aries  and  of  Libra.'  From  one  more 
passage  quoted  by  the  scholiast  of  Brahmegupta,*  it  further  appears,  that 
he  reckoned  1986120000  years  expired'  before  the  war  of  the  Bhdrata:  and 
the  duration  of  the  Culpa,  if  he  be  rightly  quoted  by  Brahmegupta,*  is 
1008  quadruple  3/M^fl«  of  4320000  years  each. 

From  these  data  it  follows  that  according  to  him,  the  equinoctial  point 
had  completed  9.65699  oscillations  at  the  epoch  of  the  war  of  the  Bhuraia. 
But  we  are  without  any  information  as  to  the  progress  made  in  the  current 
oscillation  when  he  wrote ;  or  the  actual  distance  of  the  equinox  from  the 
beginning  of  Mesha :  the  position  of  which,  also,  as  by  him  received,  is 
uncertain. 

His  limit  of  the  motion  in  trepidation,  24°,  was  evidently  suggested  to  him 
^by  the  former  position  of  the  colurcs  declared  by  Pa'ra'sa'ra  ;  the  exact  dif- 
ference being  23°  20'.  But  the  commencement  of  Pa'ra'sa'ra's  Aslesha,  in 
'his  sphere,  or  the  origin  of  his  siderial  Mesha,  are  unascertained.  Whether 
his  notions  of  the  duodecimal  division  of  the  Zodiac  were  taken  from  the 
Grecian  or  Egyptian  spheres,  or  from  what  other  immediate  source,  is  but 
matter  of  conjecture. 

Quotations  of  this  author  furnish  the  revolutions  of  Jupiter  in  a  yuga^ 
and  of  Saturn's  aphelion  in  a  Calpa  f  and  those  of  the  moon  in  the  latter 

'  As.  Res.  12.     213.  *  Vrihat-sanhifii.  2. 

'  '  From  the  beginning  of  Mesha  to  the  end  of  Cani/d  (Virgo),  the  half  the  ecliptic  passes  througU 
the  north.  From  the  beginning  of  Tula  to  the  end  of  (the  fishes)  Mina,  the  remaining  half  passes 
by  the  south.' 

♦  Prit'hu'daca  on  Brahm.  c.  1.  §  10  and  30.  c.  11.  §  4. 

'  Six  menus,  twenty-seven  i/vgas  and  three  quarters.  *  PrT'i-'hu'daca  on  Brahm.  c.  1.  §  12. 

^  As.  Res.  3.  215.  »  Mun.  on  Bhds.  c.  1.  §  33. 


•    AGE  OF  A'RYABHATTA.  '  '  xliii 

period:  but  the  same  passage,'  in  which  the  number  of  lunar  revolutions  in 
that  great  period  are  given,  supplies  those  of  the  sun ;  namely  4320000000 ; 
diflfering  from  the  duration  of  the  Calpa  according  to  this  author  as  cited  by 
more  ancient  compilers.  The  truth  is,  as  appears  from  another  quotation,* 
that  Aryabhatta,  after  delivering  one  complete  astronomical  system,  pro- 
ceeds in  a  second  and  distinct  chapter  to  deliver  another  and  different  one  as 
the  doctrine  of  Paras' ara  ;  whose  authority,  he  observes,  prevails  in  the  Call 
age:  and  though  he  seems  to  indicate  the  Calpa  as  the  same  in  both,  he  also 
•hints  that  in  one  a  deduction  is  made  for  the  time  employed  in  creation  ;  and 
we  have  seen,  that  the  duration  of  the  Calpa  differs  in  the  quotations  of 
compilers  from  this  author.  '.'i 

The  ground  then  being  insufficient,  until  a  more  definitive  knowledge  of 
either  system,  as  developed  by  him,  be  recovered,  to  support  any  positive 
conclusion,  recourse  must  be  had,  on  failure  of  precise  proof,  to  more  loose 
presumption.  It  is  to  be  observed,  that  he  does  not  use  the  Saca  or  Sambat  of 
Vicrama'ditta,  nor  the  Saca  era  of  Sa'liva'hana  :  but  exclusively  employs 
the  epoch  of  the  war  of  the  Bharata,  which  is  the  era  of  Yudhisiit'hjra 
and  the  same  with  the  commencement  of  the  Call  yuga.  Hence  it  is  to  be 
argued,  that  he  flourished  before  this  era  was  superseded  by  the  introduction 
of  the  modern  epochas.  Vara'ha-mihira,  on  the  other  hand,  does  employ 
the  6'aca,  termed  by  him  Saca-bhupa-cala  and  Sacendra-cala :  which  the  old 
scholiast  interprets  "  the  time  when  the  barbarian  kings  called  Saca  were 
discomfited  by  Vicrama'ditya  :"'  and  Brahmegupta  uses  the  modern  Saca 
era;  which  he  expresses  by  Saca-nr1pant6,  interpreted  by  the  scholiast  of 
Bha'scara  "  the  end  [of  the  life  or  reign]  of  Vicrama'ditya  who  slew  a 
people  of  barbarians  named  Sacas."  Vara'ha-mihira's  epoch  of  Saca  ap- 
pears to  have  been  understood  by  his  scholiast  Bhatt'6tpala  to  be  the  same 
with  the  era  of  Vicrama'ditya,  which  now  is  usually  called  aSj/wz^^^;  and 
which  is  reckoned  to  commence  after  3044  years  of  the  Call  age  were  ex- 
pired: and  Brahmegupta's  epoch  of  Saca  is  the  era  of  Sa'liva'hana  begin- 
ning at  the  expiration  of  31/9  years  of  the  Cali  yuga :  and  accordingly  this 
number  is  specified  in  his  Brahma-siddhan'ta.  When  those  eras  were  first 
introduced  is  not  at  present  with  certainty  known.  If  that  of  Vicrama'- 
ditya, dating  with  a  most  memorable  event  of  his  reign,  came  into  use 

•  Mun,oaBlds^,c,  l.^iQ — 18.  ^  Vdrt.  &niiL  Mun.  ou  Bhus.  ^  Vrihat-sanliitd. 

g2 


xliv  NOTES  AND  ILLUSTRATIONS. 

during  its  continuance,  still  its  introduction  could  not  be  from  the  first  so 
general  as  at  once  and  universally  to  supersede  the  former  era  of  Yudhish- 
t'iiira.  But  the  argument  drawn  from  Arvabhatta's  use  of  the  ancient 
epoch,  and  his  silence  respecting  the  modem,  so  far  as  it  goes,  favours  the 
presumption  that  he  lived  before  the  origin  of  the  modern  eras.  Certainly 
he  is  anterior  to  Brahmegupta,  who  cites  him  in  more  than  a  hundred 
places  by  name;  and  to  Vara'ha-mihira,  whose  compilation  is  founded, 
among  other  authorities,  on  the  Romaca  of  Sbi'shena,  and  Vdsisht'ha  of 
Vishnu-chandra,  which  Brahmegupta  aflSrms  to  be  partly  taken  from 
Arvabhat'ta.'  The  priority  of  this  author  is  explicitly  asserted  likewise 
by  the  celebrated  astronomer  Gan'es'a,  who,  in  explanation  of  his  own  un- 
dertaking, says,  "  Rules  framed  by  other  holy  sages  were  right  in  the  Trctu 
"  and  Dwdpara;  but,  in  the  present  age,  Pa'ra's'ara's.  Arvabhatta, 
"  however,  finding  his  imperfect,  after  great  lapse  of  time,  reformed  the  sys- 
"  tern.  It  grew  inaccurate  and  was  therefore  amended  by  Durgasinha, 
"  MiHiKA,  and  others.  This  again  became  insufficient :  and  correct  rules 
/'  were  framed  by  the  son  of  Jisiinu  [Brahmegupta]  founded  upon 
J*  Brahma's  revelation.  His  sytem  also,  after  a  long  time,  came  to  exhibit 
■I*'  diflferences.  Ce's'ava  rectified  it.  Now,  finding  this  likewise,  a  little  in- 
"  correct  after  sixty  years,  his  son  Gan'es'a  has  perfected  it,  and  reconciled 
"  computation  and  experience.'" 

ARyABHATTA  then  preceded  Brahmegupta  who  lived  towards  the  middle 
of  the  sixth  century  of  the  Saca  era;  and  Vara'iia-mihira  placed  by  the 
chronologers  of  Ujjayani  at  the  beginning  of  the  fifth  or  of  the  second;  (for 
they  notice  two  astronomers  of  the  name.)  He  is  prior  also  to  Vishnu 
CHANDRA,  Srishe'n'a,  and  Durgasinha;  all  of  them  anterior  to  the  second 
Vara'ha-mihira  ;  and  an  interval  of  two  or  of  three  centuries  is  not  more 
than  adequate  to  a  series  of  astronomers  following  each  other  in  the  task  of 
emendation,  which  process  of  time  rendered  successively  requisite. 
.f^  On  these  considerations  it  is  presumed,  that  Arvabhatta  is  unquestion- 
ably to  be  placed  earlier  than  the  fifth  century  of  the  Saca :  and  probably  so, 
by  several  (by  more  than  two  or  three)  centuries  :  and  not  unlikely  before  the 
commencement  of  either  Saca  or  Sambat  eras.  In  other  words,  he  flourished 
some  ages  before  the  sixth  century  of  the  Christian  era :  and  perhaps  lived  be- 
fore, or,  at  latest,  soon  after  its  commencement.    Between  these  limits,  either 

■  Brahm.  Sidd'h.  c.  U.  §  48—51.  '  Citation  by  NRfsiNHA  on  Sir.  Sidd'fi. 


VARA'HA-MIHIRA,  xlv 

the  third  or  the  fourth  century  might  be  assumed  as  a  middle  term.  We 
shall,  however,  take  the  fifth  of  Christ  as  the  latest  period  to  which  Abya- 
bhat'ta  can,  on  the  most  moderate  assumption,  be  referred. 


WRITINGS  AND  AGE  OF  VARAHA-MIHIRA. 

This  distinguished  astrological  writer,  a  native  of  Ujjayani,  and  son  of 
AniTrADASA,'  was  author  of  a  copious  work  on  astrology,  compiled,  and,  as 
he  declares,  abridged  from  earlier  writers.  It  is  comprised  in  three  parts; 
the  first  on  astronomy ;  the  second  and  third,  on  divination  :  together  con- 
stituting a  complete  course.  Such  a  course,  he  observes  in  his  preface  to 
the  third  part,  has  been  termed  by  ancient  writers  Sanhitd,  and  consists  of 
three  Scand'has  or  parts :  the  first,  which  teaches  to  find  a  planet's  place  by 
computation  (ganita),  is  called  tantra;  the  second,  which  ascertains  lucky 
and  unlucky  indications,  is  named  hora;  it  relates  chiefly  to  nativities, 
journeys,  and  weddings ;  the  third,  on  prognostics  relative  to  various  mat- 
ters, is  denominated  Sachd.  The  direct  and  retrograde  motions  of  planets, 
with  their  rising  and  setting,  and  other  particulars,  he  goes  on  to  say,  had 
beeii  propounded  by  him  in  a  treatise  termed  Carana,  meaning,  as  the  scho- 
liast remarks,  his  compilation  entitled  Pancha-sidd'hd7iticd :  Avhich  consti- 
tutes the  first  and  astronomical  portion  of  his  entire  work.  What  relates  to 
the  first  branch  of  astrology  (hard),  the  author  adds,  had  likewise  been  de- 
livered by  him,  including  nativities  and  prognostics  concerning  journeys  and 
weddings.  These  astrological  treatises  of  his  author,  the  scholiast  observes, 
are  entitled  Vrihat-jdtaca,  Vrlhad-ydtrd,  and  Vrthad-vivdha-patala.  The 
author  proceeds  to  deliver  the  third  part  of  his  course,  or  the  second  on 
divination,  omitting,  as  he  says,  superfluous  and  pithless  matter,  which 
abounds  in  the  writings  of  his  predecessors  :  such  as  questions  and  replies  in 
dialogue,  legendary  tales,  and  the  mythological  origin  of  the  planets. 

'  Vrihat-j&taca,  c.  26  §  5;  where  the  author  so  describes  himself.  His  scholiast  also  calls  him 
Avantka  from  his  native  city  Ujjayani,  and  terms  him  a  Magadha  Brahmen,  and  a  compiler  of 
astronomical  science.  BnATToTPAf.A  on  Fr/.-^Vif.  1.  The  same  scholiast  similarly  describes  him 
in  the  introduction  of  a  commentary  on  a  work  of  bis  ton  Prithuyas'as. 


xlvi  NOTES  AND  ILLUSTRATIONS. 

The  tliird  part  is  extant,  and  entire ;  and  is  generally  known  and  cited  by 

•  the  title  of  Vrihat-sanhitd ;   or  great  course  of  astrology :  a  denomination 

well  deserved ;  for,  notwithstanding  the  author's  professions  of  conciseness, 

it  contains  about  four  thousand  couplets  distributed  in  more  than  a  hundred 

chapters,  or  precisely  (including  the  metrical  table  of  contents)  106. 

Of  the  second  part,  the  first  section,  on  casting  of  nativities,  called  Vrihat- 
jdtaca,  is  also  extant,  and  comprises  twenty-five  chapters ;  or,  with  the  me- 
trical table  of  contents  and  peroration  which  concludes  it,  twenty-six.     The 
other  two  sections  of  this  part  of  the  course  have  not  been  recovered,  though 
probably  extant  in  the  hands  of  Hindu  astrologers. 

The  scholia  of  the  celebrated  commentator  of  this  author's  works,  who  is 
usually  called  Bkatt^tpala,  and  who  in  several  places  of  his  commentary 
names  himself  Utpala,  (quibbling  with  simulated  modesty  on  his  appella- 
tion ;  for  the  word  signifies  stone  •})  are  preserved  ;  and  are  complete  tor  the 
third  part  of  the  author's  course ;  and  for  the  first  section  of  the  second : 
and  the  remainder  of  it  likewise  is  probably  extant ;  as  the  copy  of  the  first 
section,  in  the  possession  of  the  author  of  this  dissertation,  terminates  abrupt- 
ly after  the  commencement  of  the  second. 

This  commentator  is  noticed  in  the  list  of  authorities  furnished  by  the 
astronomers  of  Ujjayan'i ;  and  is  there  stated  as  of  the  year  890  of  the  ^aca 
era  (A.  D.  1068).  Sir  JVillia7n  Jo  sis  supposed  him  to  be  the  son  of  the 
author,  whose  work  is  expounded  by  him.  The  grounds  of  this  notion, 
which  is  not,  however,  very  positively  advanced  by  that  learned  orientalist,* 
are  not  set  forth.  No  intimation  of  such  relation  of  the  scholiast  to  his 
author,  appears  in  the  preface  or  the  conclusion,  nor  in  the  colophon,  of  the 
commentary  which  has  been  inspected:  nor  in  the  body  of  the  work  ;  where 
the  author  is  of  course  repeatedly  named  or  referred  to,  without  however 
any  addition  indicative  of  filial  respect,  as  Hindu  writers  usually  do  employ 
when  speaking  of  a  parent  or  ancestor.  Neither  is  there  any  hint  of  rela- 
tionship in  the  commentary  of  the  same  scholiast  Bhatt6tpala  on  a  brief 
treatise  of  divination,  entitled  Prasna-cdshti,  comprizing  fifty-six  stanzas,  by 

'  Preface  to  the  Commentary  on  the  Vrihat-j&lara.  Conclusion  of  the  gloss  on  ch.  18  of  VrVtat- 
sanhitA,  &c.  '  Stone  (utpalaj  frames  the  raft  of  interpretation  to  cross  the  ocean  composed  by 
Vardhamiliira.' 

*  The  words  are  '  the  comment  written  by  Bhattotpala,  who,  it  seems,  was  a  son  of  the  au- 
thor.'   As.  Res.  2.  390. 


VARA'HA-MIHIRA.    ,i^^  xlvii 

PriVhuyas'as  son  of  Varaha-mihira.     The  suggestion  of  the  filial  rela- 
tion of  the  scholiast  is  probably  therefore  a  mere  error. 

The  Pancha-sidcT hanticd  of  Vara'ha-mihira  has  not  yet  been  recovered; 
and  is  only  at  present  known  from  quotations  of  authors ;  and  particularly  a 
number  of  passages  cited  from  it  by  his  scholiast  in  couise  of  interpreting 
his  astrological  writings.  An  important  passage  of  it  so  quoted  will  be 
noticed  forthwith. 

It  is  a  compilation,  as  its  name  implies,  from  five  sidd'hdntas ;  and  they 
are  specified  in  the  second  chapter  of  the  Vrthat-sanhitd,  where  the  author 
is  enumerating  the  requisite  qualifications  of  an  astronomer  competent  to 
calculate  a  calendar :  among  other  attainments  he  requires  him  to  be  con- 
versant with  time  measured  by  yugas,  &c.  as  taught  in  the  five  sidd'hdntas 
upon  astronomy  named  Paulisa,  Romaca,  Vdsisht'ha,  Saura,  and  Paitdmaha^ 

The  title  of  Vara'ha-mihira's  compilation  misled  a  writer  on  Hindu 
astronomy*  into  an  unfounded  supposition,  that  he  was  the  acknowledged 
author  of  the  five  sidd'hdntas ;  the  names  of  two  of  which  moreover  are 
mistaken,  Soma  and  Paulastya  being  erroneously  substituted  for  Romaca  and 
Paulisa.  These  two,  as  well  as  the  Vdsisht'ha,  are  the  works  of  known 
authors,  namely,  Pulis'a,  Srishena,  and  Visiinu-chandra;  all  three  men- 
tioned by  Brahmegupta:  by  whom  also  the  whole  five  sidd'hdntas  are 
noticed  under  the  very  same  names  and  in  the  same  order  f  and  who  has 
specified  the  authors  of  the  first  three.*  The  Vdsisht'ha  of  Vishnu-chandra 
was  indeed  preceded  by  an  earlier  work  (so  entitled)  of  an  unknown  author, 
from  which  that,  as  well  as  the  Romaca,  is  in  part  taken;'  and  it  may  be 
deemed  an  amended  edition :  but  the  Romaca  and  Paulisa  are  single  of  the 
names ;  and  no  Hindu  astronomer,  possessing  any  knowledge  of  the  history 
of  the  science  cultivated  by  him,  ever  could  imagine,  that  Vara'ha-mihira 
composed  the  work  which  takes  its  name  from  Pulis'a,  the  distinguished 
founder  of  a  sect  or  school  in  astronomy  opposed  to  that  of  Arya-bhat'ta. 

The  passage  of  the  Pancha-sidd'hdnticd   cited   by   the   scholiast,*   and 

^  promised  to  be  here  noticed,  has  been  quoted  in  an   essay  inserted  in  the 

researches  of  the  Asiatic  Society,'  as  well  as  a  parallel  passage  of  the  Vuhat- 


'  Vrihat-tanhiti,  c.  2.  §  7.  *  As.  Res.  8.  196. 

»  Brahm.  SidiTh.  c.  14.  ♦  Ibid.  c.  11.  '  Ibid, 

•  On  Vrlhat-sanhiti,  c.  2.  '  As.  Res.  12. 


xlviii  NOTES  AND  ILLUSTRATIONS. 

satihitA,^  both  relative  to  the  ancient  and  actual  position  of  the  colurcs ;  anct 
deemed  parallel  (though  one  be  less  precise  than  the  other);  since  they  are 
cited  together  as  of  the  same  author,  and  consequently  as  of  like  import, 
by  the  scholiast.'  The  text  of  the  Vrihat-sanhitd  is  further  authenticated  by 
a  quotation  of  it  in  the  commentary  of  PriVhu'daca  on  Brahmegupta;' 
and  the  former  position  of  the  colures  is  precisely  that  which  is  described  in 
the  calendar  appendant  on  the  Vedas*  and  which  is  implied  in  a  passage  of 
Pa'ra's'ara,  concerning  the  seasons,  which  is  quoted  by  Bhatt6tpala. 

The  position  of  the  colures,  affirmed  as  actual  in  his  time  by  Vara'ha- 
MiHiRA,  in  the  Vrthat-sanhitd,  implies  an  antiquity  of  either  1216  or  1440 
years  before  A.  D.  1800,  according  to  the  origin  of  the  ecliptic  determined 
from  the  star  Chitrd  (Spica  virginis)  distant  either  180°  or  183°  from  it;  or 
a  still  greater  antiquity,  if  it  be  taken  to  have  corresponded  more  nearly 
with  the  Grecian  celestial  sphere.  The  mean  of  the  two  numbers  (disre- 
garding the  surmise  of  greater  antiquity,)  carries  him  to  A.  D.  472.  If 
Vara'ha-mihira  concurred  with  those  Indian  astronomers,  who  allow  an 
oscillation  of  the  equinox  to  27'  in  1800  years,  or  a  complete  oscillation  of 
that  extent  both  E.  and  W.  in  7200  years,  he  must  have  lived  soon  after  the 
year  3600  of  the  Call  yuga,  or  421  Saca,  answering  to  A.  D.  499;  which  is 
but  six  years  from  the  date  assigned  to  him  by  the  astronomers  of  Ujjayani: 
and  twenty-seven  from  the  mean  before  inferred. 

It  is  probable,  therefore,  that  he  flourished  about  the  close  of  the  fifth 
century  of  the  Christian  era;  and  this  inference  is  corroborated  by  the 
mention  of  an  astrologer  of  this  name  in  the  Panchat antra,  the  Sanscrit  ori- 
ginal of  the  fables  of  Pilpay  translated  in  the  reign  of  Nusuirvan,  King  of 
Persia,  in  the  latter  part  of  the  sixth  century  and  beginning  of  the  seventh.' 

To  that  conclusion  there  is  opposed  an  argument  drawn  from  a  passage  of 
the  Bhdsvati-carana ;  in  which  the  author  of  that  treatise  dated  1021  Saca 
(A.  D.  1098)  professes  to  have  derived  instruction  from  Mihira,  meaning, 
•as  is  supposed,  oral  instruction  from  Vara'ha-mihira  ;  and  the  argument 
has  been  supported  by  computations  which  make  the  Surya-siddlidnta  and 
Jdtacdniava,  the  latter  ascribed  to  Vara'ha-mihira,  to  be  both  worlis  of  the 
same  period,  and  as  modern  as  the  eleventh  century.' 

■  C.  3.  §  1  and  2.  »  On  Vrt.  Sanh.  c.  2. 

'  Brahm.  Sidd'A.  c.  11,  §  54.  *  As.  Res.  8.  469. 

'  Prel'.  to  the  Sansc.  Hitopadcsa.     Edit.  Serampur.  *  As.  Res.  6.  572. 


VARA'HA-MIHIRA.  xlix 

To  this  it  has  been  replied,  that  the  Mihira,  from  whom  Sata'nanda, 
author  of  the  Bh/isicati,  derived  instruction,  is  not  the  same  person  or  per- 
sonage with  die  author  of  tiic  I'rl/iaf  sanhitd;  if  indeed  Sata'nanda's  ex- 
pression do  intend  the  same  name,  Vara  ha.'  That  expression  must  he 
allowed  to  be  a  very  imperfect  designation,  which  omits  half,  and  that  the 
most  distinctive  half,  of  an  apj^ellation  :  and  it  is  not  such,  as  would  be 
applied  by  a  contemporary  and  auditor  to  an  author  and  lecturer,  whose 
celebrity  could  not  yet  be  so  generally  diffused,  as  to  render  a  part  of  his 
name  a  sufficient  intimation  of  the  remainder :  without  previous  and  well 
established  association  of  the  terms.  But  even  conceding  the  interpretation, 
it  would  then  be  right  to  admit  a  third  Vara'ha-mihira,  besides  the  two 
noticed  by  the  chronologists  of  Ujjayani;  and  the  third  will  be  an  astrono- 
mer, contemporary  with  Raja  Bh6ja-deva  ;  and  the  preceptor  of  Sata'- 
nanda;  and  author  of  the  Jatacarriara,  supposing  this  treatise  on  nativities 
to  be  properly  ascribed  to  an  author  bearing  that  name,  and  to  be  on  suffi- 
cient grounds  referred  to  the  eleventh  century. 

There  remains  to  be  here  noticed  another  treatise  on  casting  of  nativities, 
to  which  the  same  favourite  name  of  a  celebrated  astrologer  is  affixed.  It 
is  a  concise  tract  entitled  Laghu-jataca:  and  its  authenticity  as  a  work  of 
the  astrologer  of  Ujjayani  is  established  by  the  verifying  of  a  quotation  of 
the  scholiast  Bhatt6tpala;  who  cites  a  passage  of  his  author's  compen- 
dious treatise  on  the  same  subject  (swalpa  jdtaca)  in  course  of  expounding 
a  rule  of  prognostication  concerning  the  destination  of  a  prince  to  the  throne 
and  his  future  character  as  a  monarch  (Vr^ihatjataca,  11.  1.).  That  passage 
occurs  in  the  Laghujdtaca  (Misc.  Chap.).  It  is  hardly  to  be  supposed,  that 
the  same  writer  can  have  given  a  third  treatise  on  the  same  subject  of 
nativities,  entitled  Jdtacdrriava. 

The  question  concerning  the  age  of  the  Surya-siddhdnta  remains  for  con- 
sideration. It  is  a  very  material  one;  as  both  Vara'ha-mihira  and  Brah- 
jiEGUPTA  speak  of  a  Saura  (or  Solar)  siddhdnia,  which  is  a  title  of  the  same 
import:  and,  unless  a  work  bearing  this  title  may  have  existed  earlier  than 
the  age,  which  is  assigned,  for  reasons  to  be  at  a  future  time  examined,  to 
the  Surya-sidd' hdnta,  the  conclusions  respecting  the  periods  when  they  re- 
spectively wrote,  are  impeached  in  the  degree  in  which  those  grounds  of 
calculation  may  deserve  confidence.  Those  grounds  in  detail  will  be  dis- 
cussed at  a  separate  opportunity.     But  independently  of  this  discussion  of 

'  As.  Res.  12.  p.  224. 

h 


1  NOTES  AND  ILLUSTRATIONS. 

their  merits,  sufficient  evidence  does  exist  to  establish,  that  more  than  one 
edition  of  a  treatise  of  astronomy  has  borne  the  name  of  Surya  (with  its 
synonyma)  the  sun.  For  Lacshmidasa  cites  one  under  the  title  of  Vrihat 
surya-sidd'hAnta}  (for  a  passage  which  the  current  solar  Sidd'hdnta  does  not 
exhibit;)  in  contradistinction  to  another  more  frequently  cited  by  him  with- 
out the  distinctive  epithet  of  Vrihat :  and  in  these  latter  instances  his  cjuota- 
tions  admit  of  verification.  A  reference  of  Bha'scara  to  a  passage  of  the 
Saura,  or,  as  explained  by  Iris  own  annotation,  t\\QSurya-sidd'h(inta,i\ots  not 
agree  with  the  text  of  the  received  Siirya-sidd' hatiia.^  His  commentators 
indeed  do  not  unreservedly  conclude  from  the  discrepancy  a  difterence  of 
the  work  quoted,  and  that  usually  received  under  the  same  title.  Yet  the 
inference  seems  legitimate.  At  all  events  the  quotation  from  the  Vrilutt- 
surya-sidd'hdnta,  in  the  Ganita-tatwa-chintdmani  of  Lacshmida'sa,  proves 
beyond  question,  that  in  that  commentator's  o])inion,  and  consistently  with 
his  knowledge,  more  than  one  treatise  bearing  the  same  name  existed. 

There  is  evidence  besides  of  Arabian  writers,  that  a  system  of  astronomy 
bearing  the  equivalent  title  of  Area  (Solar)  was  one  of  three,  which  were 
found  by  them  current  among  the  Hindus,  when  the  Arabs  obtained  a 
knowledge  of  the  Indian  astronomy  in  the  time  of  the  Abbasside  Khalifs, 
about  the  close  of  the  eighth  century  or  commencement  of  the  ninth  of  the 
Christian  era.'  Arcand,  the  name  by  which  the  Arabs  designate  one  of  those 
three  astronomical  systems,  assigning  it  as  an  Indian  term,  is  the  well  known 
corruption  of  Area  in  the  common  dialects,  and  is  familiar  in  the  application 
of  the  same  word  as  a  name  of  a  plant  (Asclepias  Gigantea)  which,  bearing 
all  the  synonyma  of  the  sun,  is  called  vulgarly  Acand,  or  Arcand. 

The  solar  doctrine  of  astronomy  appears  then  to  have  been  known  bv  this 
name  to  the  Arabians  as  one  of  three  Indian  astronomical  systems  a  thousand 
years  ago.  The  fact  is  that  both  the  title  and  the  system  are  considerably  more 
ancient.  Revisions  of  systems  occasionally  take  place;  like  Brahmegupta's 
levisal  of  the  Brahma-sidd'hdnta,  to  adapt  and  modernise  them  ;  or,  in  other 
words,  for  the  purpose,  as  Brahmegupta  intimates,  of  reconciling  compu- 
tation and  observation.  'i\\c  Surya  ox  Arca-sidd'hdnta,  no  doubt,  has  under- 
gone this  process ;  and  actually  exhibits  manifest  indicatioiis  of  it.* 

In  every  view,  it  is  presumed,  that  any  question  concerning  the  age  of 
the  present  text  of  the  Surya-siddhdnta,  or  determination  of  that  question, 

•  Ght.  tawat  chiiit.  on  Spherics  of  Siromarii,  ch.  4.  Cons,  of  Sines.  '  As.  Res.  12. 

'  See  Note  N.  *  As.  lies,  2.  235. 


1 

J 


VARAHA-MIIIIRA.  U 

will  leave  mitouchefl  the  evidence  for  the  age  of  the  author  of  the  Vrihat- 
sanhita,  Vara'ha-mihira,  son  of  Adityada'sa,  an  astrologer  of  Ujjayani, 
who  appears  to  have  flourished  at  the  close  of  the  fifth,  or  beginning  of  the 
sixth  century  of  the  Christian  era.  He  was  preceded,  as  it  seems,  by  another 
of  the  same  name,  who  lived,  according  to  the  chronologists  of  Ujjayani,  at 
the  close  of  the  second  century.  He  may  have  been  followed  by  a  third, 
who  is  said  to  have  flourished  at  the  Court  of  Raja'  Bhoja-de'va  of  Dhara, 
and  to  have  had  SataVanda,  the  author  of  the  Bhdsvati,  for  his  scholar. 


L. 

INTRODUCTION  AND  PROGRESS  OF  ALGEBRA  AMONG 

THE  ITALIANS. 

Leonardo  of  Pisa  was  unquestionably  the  first  who  made  known  the 
Arabian  Algebra  to  Christian  Europe.  This  fact  was,  indeed,  for  a  time 
disputed,  and  the  pretensions  of  the  Italians  to  the  credit  of  being  the  first 
European  nation,  which  cultivated  Algebra,  were  contested,  upon  vague 
surmises  of  a  possible,  and  therefore  presumed  probable,  communication  of 
the  science  of  Algebra,  together  with  that  of  Arithmetic,  by  the  Saracens  of 
Spain  to  their  Christian  neighbours  in  the  Peninsula,  and  to  others  alleged 
to  have  resorted  thither  for  instruction.  The  conjecture,  hazarded  by  Wallis 
(Algebra  historical  and  practical)  on  this  point,  was  assisted  by  a  strange 
blunder,  in  which  Blancanus  was  followed  by  Vossius  and  a  herd  of  sub- 
sequent writers,  concerning  the  age  of  Leonardo,  placed  by  them  precisely 
two  centuries  too  low.  The  claims  of  the  Italians  in  his  favour,  and  for 
themselves  as  his  early  disciples,  were  accordingly  resisted  with  a  degree  of 
acrimony  (Gua.  Mem.  de  I'Acad.  des  Sc.  1741.  p.  436.)  which  can  only  be 
accounted  for  by  that  disposition  to  detraction,  which  occasionally  manifests 
itself  in  the  literary,  as  in  the  idler,  walks  of  society.  The  evidence  of  his 
right  to  acknowledgments  for  transplanting  Arabian  Algebra  into  Europe, 
was  for  a  long  period  ill  set  forth:  but,  when  diligently  sought,  and  care- 
fully adduced,  doubt  was  removed  and  opposition  silenced.' 

•  Montucla,  2d  Ed.  Addns. 
h2 


lii  NOTES  AND  ILLUSTRATIONS. 

The  merit  of  vindicating  his  claim  belongs  chiefly  to  Cossali.*  A  manu- 
script of  Leoxardo's  treatise  on  Arithmetic  and  Algebra,  bearing  the  title 
oi  Liber  Abbaci  compositus  a  Leonardo  Jilio  Bonacci  Pisatio  in  anno  1202, 
was  found  towards  the  middle  of  the  last  century  by  Targioni  Tozzetti*  in 
the  Magliabecchiau  library  at  Florence,  of  which  he  had  the  care ;  and 
another  work  of  that  author,  on  scjuare  numbers,  was  afterwards  found  by 
the  same  person  inserted  in  an  anonymous  compilation,  treating  of  compu- 
tation, (un  trattato  d'Abbaco),  in  the  library  of  a  royal  hospital  at  the  same 
place.  A  transcript  of  one  more  treatise  of  the  same  writer  was  noticed  by 
Tozzetti  in  the  Magliabecchiau  collection,  entitletl  Leotia?-di  Pisani  dejiliis 
Bonacci  Practica  Geomctrice  composita  anno  1220.  The  subject  of  it  is 
confined  to  mensuration  of  land;  and,  being  mentioned  by  the  author  in  his 
ej)istle  prefixed  to  the  revised  Liber  Abbaci,  shows  the  revision  to  be  of  later 
date.  It  appears  to  be  of  1228.^  Tozzetti  subsequently  met  with  a  second 
copy  of  the  Liber  Abbaci  iu  INlagliabecchi's  collection:  but  it  is  described  by 
him  as  inaccurate  and  incomplete.*  A  third  has  been  since  discovered  in  the 
lliccardian  collection,  also  at  Florence:  and  a  fourth,  but  imperfect  one,  was 
communicated  by  Nelli  to  Cossali.*  No  diligence  of  research  has,  how- 
ever, regained  any  trace  of  the  volume  which  contained  Leonardo's  treatise 
on  square  numbers:  the  library,  in  which  it  was  seen,  having  been  dispersed 
previously  to  Cossali's  inquiries. 

It  appears  from  a  brief  account  of  himself  and  his  travels,  and  the  motives 
of  his  undertaking,  which  Leonardo  has  introduced  into  his  preface  to  the 
Liber  Abbaci,  that  he  travelled  into  Egypt,  Barbary,  Syria,  Greece,  and 
Sicily  ;  that  being  in  his  youth  at  Bugia  in  Barbary,  where  his  father 
Bonacci  held  an  employment  of  scribe  at  the  Custom  House  by  appointment 
from  Pisa,  for  Pisan  merchants  resorting  thither,  he  was  there  grounded  in 
the  Indian  method  of  accounting  by  nine  numerals;  and  that  finding  it  more 
commodious,  and  far  preferable  to  that  which  was  used  in  other  countries 
visited  by  him,  he  prosecuted  the  study,*  and  with  sonie  additions  of  his  own, 
and  taking  some   things  from  Euclid's  geometry,  he  undertook  the  com- 

■  Origine,  &c.  dell'Algelira.     Parma  1797.  ^  Fiaggi,  land  \\.     Edit.  1751  — 1754. 

'  Cossali,  Origine,  &c.  c.  1.  §  5.  ♦  Viaggi,  ii.     Edit.  1768. 

'  Origine,  &c.  deli'  Algebra,  c.  2.  §  1. 

*  Quare  amplectens  strictius  ipsum  inodum  Yndbrum,  et  actentiiis  studens  in  eo,  ex  proprio 
sensu  quxdara  addens,  et  quxdam  e.\  subtilitatibus  Eiiclidis  geometria;  artis  apponens,  &c. 


ALGEBRA  AMONG  THE  ITALIANS.  liii 

position  of  the  treatise  in  question,  that  "  the  Latin  race  might  no  longer  be 
found  deficient  in  the  complete  knowledge  of  that  method  of  computation." 
In  the  epistle  prefixed  to  the  revision  of  his  work  he  professes  to  have  taught 
the  complete  doctrine  of  numbers  according  to  the  Indian  method.^ 

His  peregrinations  then,  and  his  study  of  the  Indian  computation  through 
tlie  medium  of  Arabic,  in  an  African  city,  took  place  towards  the  close  of 
the  twelfth  century;  the  earliest  date  of  his  work  being  A.  C.  1202. 

He  had  been  preceeded  by  more  than  two  centuries,  in  the  study  of  arith- 
metic under  Muhannnedan  instructors,  by  Gerbert (the Pope  SilvesterII.^), 
whose  ardour  for  the  acquisition  of  knowledge  led  him  at  the  termination  of 
a  two  years  noviciate,  as  a  Benedictine,  to  proceed  by  stealth  into  Spain, 
where  he  learnt  astrology  from  the  Saracens,  and  with  it  more  valuable 
science,  especially  arithmetic.  This,  upon  his  return,  he  comnmnicated  to 
Christian  Europe,  teaching  the  method  of  numbers  under  the  designation  of 
Abacus,  a  name  apparently  first  introduced  by  him,  (rationes  luimerorum 
Abaci,')  by  rules  abstruse  and  difficult  to  be  understood,  as  William  of 
Malmesbury  affirms:  Abacum  certeprijnus a  Saracenis rapiens,  regulas  dedit, 
yuceasitdantibus  Abacistis  vix  intelliguntur.*  It  was  probably  owing  to  this 
obscurity  of  his  rules  and  manner  of  treating  the  Arabian,  or  rather  Indian 
arithmetic,  that  it  made  so  little  progress  between  his  time  and  that  of  the 
Pisan. 

Leo.vahdo's  work  is  a  treatise  of  Arithmetic,  terminated,  as  Arabic  treatises 
of  computation  are  similarly,'  by  the  solution  of  equations  of  the  two  first 
degrees.  In  the  enumeration  and  exposition  of  the  parts  comprised  in  his 
fifteenth  chapter,  which  is  his  last,  he  says,  Tertia  erit  super  modumAlgebrce  et 
Almucabalce ;  and,  beginning  to  treat  of  it,  lucipit  pars  tertia  de  solutione 
quarundam  qucestionum  secundum  modujn  Algebra  et  Ahnucabalce,  scilicet  op- 
pnsitionis  et  restaurationis.  The  sense  of  the  Arabic  terms  are  here  given  in 
the  inverse  order,  as  has  been  remarked  by  Cossali,  and  as  clearly  appears 
from  Leonardo's  process  of  resolving  an  equation,  which  will  be  hereafter 
shown. 

Plenam   iiumeroruni  doctrinam   edidi   Yndoruni,  fjiietn  modum  in  ipsa  scienlia  piaestaiitiorem 
elegi. 

*  Arch  bishop  in  992;  Pope  in  r)C)g-^  died  in  1003. 

'  Ep.  prefixed  to  his  Treatise  De  Nuraerorum  Divisione.     Cerb.  Ep.  JfiO.  (Ed.  ifill.) 

*  Ue  Gestis  Anglorum,  c.  2. 

»  See  Mr.  Strachey's  examination  of  the  Khuldsatu'lhia&b,  As.  Res.  J  2.     Early  History  of  Alg. 


liv  NOTES  AND  ILLUSTRATIONS. 

He  premises  the  observation,  tliat  in  nunil«;r  three  considerations  are  dis- 
tinguished: one  simple  and  absohjte,  which  is  that  of  number  in  itself:  the 
other  two,  relative;  being  those  of  root  and  of  square.  The  latter,  as  he 
adds,  is  called  census,  which  is  the  term  he  afterwards  employs  throughout. 

It  is  the  equivalent  of  the  Arabic  M//1,  which  properly  signifies  wealth, 
estate;  and  census  seems  therefore  to  be  here  employed  by  Leonardo,  on 
account  of  its  correspondent  acceptation;  (quicquidfortunarum  quis  habet. 
Steph.)  in  like  manner  as  he  translates  the  Arabic  shai  by  res,  thing,  as  a 
designation  of  the  root  unknown. 

He  accoi-dingly  proceeds  to  observe,  that  the  simple  numl)er,  the  root,  and 
the  square  (census),  are  equalled  together  in  six  M'^ays:  so  that  six  forms  of 
equality  are  distinguished:  the  three  first  of  which  are  called  simple;  and 
the  three  others  compound.  The  order,  in  which  he  arranges  them,  is  pre- 
cisely that  which  is  copied  by  Paciolo.*  It  differs  by  a  slight  transposition 
from  the  order  in  which  they  occur  in  the  earliest  Arabic  treatises  of  Alge- 
bra;* and  which,  no  doubt,  was  retained  in  the  Italian  vei-sion  from  the 
Arabic  executed  by  Guglielmo  Di  Lunis,  and  others  who  are  noticed  by 
CossALi  upon  indications  which  are  pointed  out  by  him.'  For  Paciolo 
cautions  the  reader  not  to  regard  the  difference  of  arrangement,  as  this  is  a 
matter  of  arbitrary  choice.*  Leonahdo's  six-fold  distinction,  reduced  to  the 
modem  algebraic  notation,  is  1st,  x^=p  x.  2d,  a:*=n.  3d, />  .r=?z.  4tli, 
x^+p  x—n.  5th,  p  x  +  n=x^.  6th,  x''  +  n=p  x.  In  Paciolo's  abridged  no- 
tation it  is  1st,  c°  e  c*.  2d,  c°  e  n".  3d,  c*  e  n°,  S^x.'  The  Arabic  arrange- 
ment, in  the  treatise  of  the  Khuwarezmite,  is,  1st,  x''=p  x.  2d,  x"=n.  '3(\, 
p  x=n.  4th,  a^+p  x=n.  2d,  x"  +  n=p  x.  3d, />  a'  +  «=.r'.  Later  compi- 
lations transfer  the  third  of  these  to  the  first  place." 

Like  the  Arabs,  Leonardo  omits  and  passes  unnoticed  the  fourth  form  of 
quadratic  equations,  .r*+// .r  +  M=o.  It  could  not,  indeed,  come  within  the 
Arabian  division  of  equations  into  simple,  between  species  and  species,  and 
compound,  between  one  species  and  two:'  quantity  being  either  stated 
affnmatively,  or  restored  in  this  Algebra  to  the  positive  form.  Paciolo 
expressly  observes,  that  in  no  other  but  these  six  ways,  is  any  equation  be- 


•  Summa  de  Arithinetica,  &c.  »  See  Note  N.  '  Originc,  &c.  deU'Alg. 

♦  Summa,  8. 5. 5.  '  Summa,  8. 5.  5.  '  Khulasatu'l  hisdb. 
'  Khuldsatu'l  his/lb. 


ALGEBRA  AMONG  THE  ITALIANS.  Iv 

tween  those  quantities  possible:  Altramente  che  i  quest i  6  discorsi  modi  non  e 
possible  alciina  loro  equatione. 

Leoxardo's  resolution  of  the  three  simple  cases  of  equation  is  not  ex- 
hibited by  CossALi.  It  is,  however,  the  same,  no  doubt,  with  that  which  is 
taught  by  Paciolo  ;  and  which  precisely  agrees  with  the  rules  contained  in 
the  Arabic  books.'  To  facilitate  comparison,  and  obviate  distant  reference, 
Paciolo's  rules  are  here  subjoined  in  fewer  words  than  he  employs. 

J  St,  Divide  the  things  by  the  squares  [coefficient  by  coefficient],  the 
quotient  is  the  value  of  thing. 

2d,  Divide  the  number  by  the  squares  [by  the  coefficient  of  the  square], 
the  root  of  the  quotient  is  the  value  of  thing. 

3d,  Divide  the  number  by  the  things  [that  is,  by  the  coefficient],  the 
quotient  is  the  value  of  thing.^ 

The  resolution  of  the  three  cases  of  compound  equations  is  delivered  by 
CossALi  from  Leonaudo,  contracting  his  rugged  Latin  into  modern  Alge- 
braic form. 

1st,  Bej^+/>x=n.     Then  .r=— i/>  + v/ (i/>'  +  7j). 

2d,  Be  J-  =p  x  +  n.     Then  a- =-i  />  +  v^  (i  />'  +  «)• 

3d,  Be  x-  +  n=p  x.  Then,  if  ^  p''^n,  the  equation  is  impossible.  If 
ip^  =  n,  then  x=^  p.     If  i  p'7«,  then  x=i  p-/  (i  p^-n),  or  =-Lp+  ^ 

Up'-")- 

He  adds  the  remark:  Ei  sic,  si  non  solvetur  quastio  cum  diminutione,  solve- 
tur  cum  additione. 

The  rules  are  the  same  which  are  found  in  the  Arabic  treatises  of  algebra.' 
The  same  rules  will  be  likewise  found  in  the  work  of  Paciolo,  expressed 
with  his  usual  verboseness  in  his  Italian  text:  to  which,  in  this  instance,  he 
has  added  in  the  margin  the  same  instructions  delivered  in  a  conciser  form  in 
Latin  memorial  verses.  As  they  are  given  at  length  by  Montucla,  it  is  un- 
necessary to  cite  them  in  this  place.  On  the  subject  of  the  impossible  case 
Paciolo  adds,  as  a  Notandum  utilissimuni,  '  Sel  numero  qual  si  trova  in  la 
detta  equatione  accotnpagnato  con  lo  censo,  sel  non  eminore  o  veramente  equale 
al  quadrato  de  la  mita  de  le  cose,  el  caso  essere  insolubik :  e  pur  consequente 
detto  agguagUamenlo  non  potere  avvenire  per  alcun  modo.'     Summa,  8.  4.  12. 

Concerning  the  two  roots  of  the  (juadratic  equation  in  the  other  case, 

'  See  Note  N  ;  and  As.  Res.  12.  *  Summa,  8.  5.  6.  '  See  Note  N. 


IH  NOTES  AND  ILLUSTRATIONS. 

under  the  same  head,  he  thus  expands  the  short  concluding  remark  of  Lko- 
NARDO:  Sia  che  I'uno  e  I'aliro  modo  satisja  al  tema:  ma  a  Ic  volte  se  havi  la 
veriia  a  Vuno  modo,  a  le  volte  a  raltro;^  el  perche,  se  cavanda  la  radice  del 
delta  remanente  de  la  mita  de  le  cose  non  satisfacesse  al  tana,  la  detta  radice 
aggiugni  a  la  mita  de  le  cose  e  averai  el  quesito :  e  mat  Ja Hera  che  a  Viino  di  lai 
modi  non  sia  satisfatta  al  quesito,  cioe  giognendo  le,  ovvero  cavando  la  del 
dimeciamento  de  le  cose.     Summa,  8.  4.  12. 

BoMBELLi  remarks  somewhat  differently  on  the  same  point.  Nei  quesiti 
alcana  volta,  ben  che  di  rado,  il  restante  7ion  serci,  ma  ben  si  la  sovima  setnpre. 
Alg.  2.  262. 

The  rules  for  the  resolution  of  compound  equations  are  demonstrated  hy 
Leonardo  upon  rectihnear  figures ;  and  in  the  last  instance  he  has  reference 
to  Euclid. — Lib.  2.  Th.  5.  There  is  room  then  to  surmise,  that  some  of  the 
demonstrations  are  among  the  additions  which  he  professes  to  have  made. 

Among  the  many  problems  which  he  proceeds  to  resolve,  two  of  which  arc 
selected  by  Cossali  for  instances  of  his  manner,  it  will  be  sufficient  to  cite 
one,  in  the  resolution  of  which  the  whole  thread  of  his  operations  is  ex- 
hibited ;  substituting,  however,  the  more  compendious  modern  signs.  His 
manner  of  conducting  the  algebraic  process  may  be  fully  understood  from 
this  single  instance. 

Problem:  To  divide  the  number  10  into  two  parts,  such  that  dividing  one 
by  the  other,  and  adding  10  to  the  sum  of  the  quotient,  and  multiplying  the 
aggregate  by  the  greater,  the  amount  is  finally  1 14. 

Let  the  right  line  a  be  the  greater  of  the  parts  sought;  which  I  call  thing 
(quarii  pono  rem):  and  the  right  line  A  ^  equal  to  10:  to  which  are  joined  in 
the  same  direction  ^</,  de,  representing  the  quotients  of  division  of  the  parts, 
one  by  the  other.  Since  a  multiplied  by  A  e  is  equal  to  114,  therefore 
aXb  g  +  aXg  d+a  +  d  e=  1 14;  and  taking  from  each  side  aXb  g,  there  will  be 
aXg  d+aXd  e=\\^—aXb  g.      lie  g  d  the  quotient  10— a,  there  will  arise 

a 
]0^a  +  aXd  e=\l^—aXb  g=]\4!—\0  a;  since  i^g"  is  equal  to  10.     Whence 
aXc?  e=104— 9«-     But  fi?e  is  the  quotient      a     :  wherefore   «*     =104>— 9  a. 

lO-a  lO-a 

So  that  fl*=  1040— 194  o +  9  a*.     Restore  diminished  things  (restaura  res  di- 

'  Compare  with  Hindu  Algebra.     Vij.-gan.  §  130  and  142. 


ALGEBRA  AMOXG  THE  ITALIANS.  Irn 

mmutas),  and  take  one  square  from  each  side  (et  extrahe  unum  censum 
ab  utraque  parte),  the  remainder  is  8  a^+ 1040=191  a;  and,  dividing  by 
eight,  «*+130=«+i«;   and   resolving    this    according    to    rule,    a=y7— 

F 

•(97)^-1 30=97-33=8:  consequently  lO-a=2. 

Besides  his  great  work  on  arithmetic  and  algebra,  Leos^akdo  was  author 
of  a  separate  treatise,  as  already  intimated,  on  square  numbers.  Reference 
b  formally  made  to  it  by  Paciolo,  who  drew  largely  from  this  source,  and 
who  mentions  Le  quali  domande  (Questions  concerning  square  numbers) 
tono  difficiUisstMe  <juanto  ala  daiunutTatione  iela  practica:  comme  sm  chi  he» 
la  scrtitinato.  Maxime  Leonardo  Pisano  in  un  particulare  tractato  eke  fa 
de  quadratis  numeris  intitulato.  Dact  con  grande  sforzo  se  ingegna  dare 
norma  e  regola  a  timili  tolutum.    Summa  1.  4.  6. 

The  directions  for  the  solntion  of  sacfa  problems  being  professedly  taken 
by  Paciolo  chiefly  from  Lkovabdo,  and  the  problems  themselves  which 
are  "f*?*^'***  by  him  being  probably  so,  it  can  be  no  difficult  task  to  restore 
tiie  lost  work  of  Leovabdo  on  this  sttbject.  The  divination  has  accordii^ly 
been  attempted  by  Cossali,  and  with  a  coosderable  degree  of  success. 
(Origine,  &c.  dell'  Algebra,  c.  5.) 

Among  problems  of  diis  sort  which  are  treated  by  Paciolo  after  Leo- 
nardo, several  are  found  in  the  canent  Arabic  treatises;  otfaers,  which 
belong  to  the  indeterminate  analysis,  occur  in  the  algebraic  treatises  of  the 
Hindus :  some,  which  are  more  properly  EHophantiDe^  may  have  been  taken 
from  the  Aralnc  tiansiation,  or  commentary,  of  die  work  of  Diophantns. 
Leovabdo's  endeavour  to  reduce  the  solution  of  such  problems  to  general 
rule  and  system,  according  to  Paciolo's  intimation  of  his  eflorts  towards 
that  end,  must  have  been  purely  his  own :  as  nothing  systematic  to  this  effect 
is  to  be  found  in  the  Arainc  treatises  of  Algebra;  and  as  he  clearly  had  no 
oommoBicatioB  thtoogh  his  Arab  mstrnctors,  nor  any  knowledge  of  the 
ttadv  inertiodfc  fiir  the  genefal  icwiliition  of  indeterminate  proUens  simple 
or  qnadiatie. 

MoxTccLA,  who  had  originally  underrated  the  perAmnance  of  Leo- 
SABDO,  seems  to  have  finally  conceded  to  it  a  merit  rather  beyond  its  desert, 
when  he  ascribes  to  that  author  the  resohition  of  certain  biquadratics  as 
derivatiTe  eqnatioiis  of  die  second  degree.     The  doivathre  rules  were. 


Iviii  NOTES  AND  ILLUSTRATIONS. 

according  to  Cardan's  aflTinnation,  added  to  the  original  ones  of  Leonakdo 
by  an  uncertain  author;  ami  placed  with  the  principal  by  Paciolo.  Car- 
dan's testimony  in  this  respect  is  indeed  not  conclusive,  as  the  passage,  in 
which  the  subject  is  mentioned,  is  in  other  points  replete  with  errors :  attri- 
buting the  invention  of  Algebra  to  Muhammed  son  of  Musa,  and  alleging 
the  testimony  of  Leonardo  to  that  point;  limiting  Leonardo's  rules  to 
four,  and  intimating  that  Paciolo  introduced  the  derivative  rules  in  the 
same  place  with  the  principal:  all  which  is  unfounded  and  contrary  to  the 
fact.  Cossali,  however,  who  seeftis  to  have  diligently  examined  Leonardo's 
remains,  does  not  claim  this  honour  for  bis  author:  but  appears  to  admit 
Cardan's  position,  that  the  derivative,  or,  as  they  are  termed  by  Paciolo, 
the  proportional  equations,  and  rules  for  the  solution  of  them,  were  devised 
by  an  uncertain  author;  and  introduced  by  Paciolo  into  his  compilation 
under  a  separate  head:  which  actually  is  the  case.     (Summa  8,  6,  2,  &c.) 

In  regard  to  the  blunder,  in  which  Montucla  copied  earlier  writers, 
respecting  the  time  when  Leonardo  of  Pisa  flourished,  he  has  defended 
himself  (i2d  edit.  Additions)  against  the  reprehension  of  Cossali,  upon  the 
plea,  that  he  was  not  bound  to  know  of  manuscripts  existing  in  certain 
libraries  of  Italy,  which  served  to  show  the  age  in  which  that  autlior  lived. 
The  excuse  is  not  altogether  valid:  for  Targioni  Tozzetti  had  announced 
to  the  public  the  discovery  of  the  manuscripts  in  question,  with  the  date, 
and  a  sufficient  intimation  of  the  contents ;  several  years  before  the  first 
volumes  of  Montucla's  History  of  Mathematics  appeared.' 

I  am  withheld  from  further  animadversion  on  the  negligence  of  an  author, 
who  has  in  other  respects  deserved  well  of  science,  by  the  consideration, 
that  equal  want  of  research,  and  in  the  very  same  instance,  has  been  mani- 
fested by  more  recent  writers,  and  among  our  own  countrymen.  Even  so 
lately  as  in  the  past  year  (1816)  a  distinguished  mathematician,  writing  in 
the  Encyclopaedia  which  bears  the  national  appellation,"  has  relied  on  obso- 
lete authorities  and  antiquated  disquisitions  concerning  the  introduction  of 
the  denary  numerals  into  Europe;  and  shown  total  unacquaintance  with 
what  was  made  public  sixty  years  ago  by  Targioni  Tozzetti  and  amply 
discussed  by  Cossali  in  a  copious  work  on  the  progress  of  Algebra  in  Italy, 

■TAaGioNi  TozzETTi's  first  volume  bears  date  1751.     His  sixth,  (the  last  of  his  first  edition) 
1754.     Montucla's  first  two  volumes  were  published  in  1758. 
*  Encycl.  Brit.  Supp.  art.  Arithmetic. 


ALGEBRA  AMONG  THE  ITALIANS.  lix 

and  in  an  earlier  one  on  the  origin  of  Arithmetic,  published  more  than 
twenty  years  since:  matter  fuih^  recognised  by  Montucla  in  his  second 
edition,  and  briefly  noticed  in  common  biographical  dictionaries.' 

In  the  article  of  the  Encyclopiedia,  to  which  reference  has  been  just  made, 
the  author  is  not  less  unfortunate  in  all  that  he  says  concerning  the  Hindus 
and  their  arithmetical  knowledge.  He  describes  the  Lilanat'i  as  "  a  short 
and  meagre  performance  headed  with  a  silly  preamble  and  colloquy  of  the 
gods."  (Where  he  got  this  colloquy  is  difficult  to  divine;  the  Lildvati 
contains  none).  "  The  examples,"  he  says,  "  are  generally  very  easy,  and 
only  written  on  the  margin  with  red  ink."  (Not  so  written  in  any  one 
among  the  many  copies  collated  or  inspected.)  "  Of  fractions,"  he  adds, 
"  whether  decimal  or  vulgar,  it  treats  not  at  all."  (See  Ch.  2.  Sect.  3.  and 
Ch.  4.  Sect.  2.  also  §  138.) 

He  goes  on  to  say,  "  the  Hindus  pretend,  that  this  arithmetical  treatise 
was  composed  about  the  year  1 185  of  the  Christian  era,  &c."  Every  thing 
in  that  passage  is  erroneous.  The  date  of  the  Lildvati  is  1 150,  at  the  latest. 
The  uncertainty  of  the  age  of  a  manuscript  does  not,  as  suggested^  affect 
the  certainty  of  the  date  of  the  original  composition.  It  is  not  true,  as 
alleged,  that  the  oriental  transcriber  is  accustomed  to  incorporate  without 
scruple  such  atlditions  in  the  text  as  he  thinks  fit.  Nor  is  it  practicable  for 
him  to  do  so  with  a  text  arranged  in  metre,  of  which  the  lines  are  numbered : 
as  is  the  case  with  Sanscrit  text  books  in  general.  Collation  demonstrates 
that  no  such  liberty  has  been  taken  with  the  particular  book  in  question. 

The  same  writer  affirms,  that  "  the  Persians,  though  no  longer  sovereigns 
of  Hindustan,  yet  display  their  superiority  over  the  feeble  Gentoos,  since 
they  generally  fill  the  offices  of  the  revenue,  and  have  the  reputation  of 
being  the  most  expert  calculators  in  the  east."  This  is  literally  and  precisely 
the  reverse  of  the  truth ;  a.s  every  one  knows,  who  has  read  or  heard  any 
thing  concerning  India. 

The  author  is  not  more  correct  when  he  asserts,  that  "  it  appears  from  a 
careful  inspection  of  the  manuscripts  preserved  in  the  different  public  libra- 
ries in  Europe,  that  the  Arabians  were  not  acquainted  with  the  denary 
numerals  before  the  middle  of  the  thirteenth  century  of  the  Christian  era." 
Leoxardo  of  Pisa  had  learned  the  Indian  numerals  from  Arabian  instruc- 

»  Diet,  Hist,  par  Chaudon  and  Delandine :  art.  Leonard  de  Pise.  7  Edit.  (1789).  Probably  in 
earlier  editions  liicewise. 

is 


Jx  NOTES  AND  ILLUSTRATIONS. 

tion  in  the  twelfth  century  and  taught  the  use  of  them  in  the  second  year 
of  tlie  thirteenth:  and  the  Arabs  were  in  possession  of  the  Indian  mode  of 
computation  by  these  numerals  so  far  back  as  the  eighth  centuiy  of  the 
Christian  era.* 

To  return  to  the  subject. 

After  Leonardo  of  Pisa,  and  before  the  invention  of  the  art  of  printing 
and  publication  of  the  first  printed  treatise  on  the  science,  by  Paciolo, 
Algebra  was  diligently  cultivated  by  the  Italian  mathematicians;  it  was  pub- 
licly taught  by  professors;  treatises  were  written  on  it;  and  recurrence  was. 
again  had  to  the  Arabian  source.  A  translation  of  "  the  Rule  of  Algebra" 
(La  Regola  dell'  Argebraj  from  the  Arabic  into  the  language  of  Italy  by 
GuGLiELMO  Di  LuNis,  is  noticcd  at  the  beginning  of  the  Ragionamento  di 
Algebra  by  Raffaelo  Caracci,  the  extant  manuscript  of  which  is  consi- 
dered by  antiquarians  to  be  of  the  fourteenth  century.*  A  translation  of  the 
original  treatise  of  Muhammed  ben  Musa  the  Khuwarezmite  appears  to 
have  been  current  in  Italy;  and  was  seen  at  a  later  period  by  both  Cardan 
and  BoMBELLi.^  Paolo  della  Pergola,  Demetrio  Bragadini,  and 
Antonio  Cornaro,  are  named  by  Paciolo  as  successively  filling  the  pro- 
fessor's chair  at  Venice;  the  latter  his  own  fellow-disciple.  He  himself 
taught  Algebra  publicly  at  Peroscia  at  two  different  periods.  In  the  pre- 
ceding age  a  number  of  treatises  on  Algorithm,  some  of  them  with  that  title;, 
others  like  Leonardo's,  entitled  De  Abaco,  and  probably  like  his  touching 
on  Algebra  as  well  as  Arithmetic,  were  circulated.  Paolo  di  Dagomari, 
in  particular,  a  mathematician  living  in  the  middle  of  the  fourteenth  century, 
obtained  the  surname  of  Deir  Abaco  for  his  skill  in  the  science  of  numbers, 
and  is  besides  said  to  have  been  conversant  with  equations  (whether  algebraic 
or  astronomical  may  indeed  be  questioned ;)  as  well  as  geometry.* 

With  the  art  of  printing  came  the  publication  of  Paciolo;  and  the  subse- 
quent history  of  the  inventions  in  Algebra  by  Italian  masters  is  too  well 
known  to  need  to  be  repeated  in  this  place. 

•  See  Note  N. 

»  CossAH,  Orig.  &c.  dell'  Algebra,  i.  7, 
^  Ibid.  1.9.     Cardan  Ars  Magn,  5. 

♦  Ibid.  i.  9.  •-. 


i 


NOTES  AND  ILLUSTRATIONS.  Ixi 

^:L:-'  M. 

ARITHMETICS  OF  DIOPHANTUS. 

.  Five  copies  of  Diophantus,  vizt.  three  in  the  Vatican  (Cossali,  Orig.  dell' 
Alg.  i.  4.  §  2.))'  Xilander's,  supposed  (Coss.  ib.  §  5)  to  be  the  same  with 
the  Palatine  inspected  by  Saumaise,  though  spoken  of  as  distinct  by  Bachet, 
(Epiit.  ad.  led.);  and  the  Parisian  used  by  Bachet  himself  (ib.);  all 
contain  the  same  text.  But  one  of  the  Vatican  copies,  believed  to  be  that 
which  BoMBELLi  consulted,  distributes  a  like  portion  of  text  into  seven  in- 
stead of  six  books.  (^Coss.  ib.  §  5.)  In  truth  the  division  of  manuscript 
books  is  very  uncertain  :  and  it  is  by  no  means  improbable,  that  the  remains 
of  Diophantus,  as  we  possess  them,  may  be  less  incomplete  and  constitute 
a  larger  portion  of  the  thirteen  books  announced  by  him  {Def.  1 1.),  than  is 
commonly  reckoned.  His  treatise  on  polygon  numbers,  which  is  surmised 
to  be  one,  (and  that  the  last  of  the  thirteen,)  follows,  as  it  seems,  the  six 
(or  seven)  books  in  the  exemplars  of  the  work,  as  if  the  preceding  portion 
were  complete.  It  is  itself  imperfect :  but  the  manner  is  essentially  different 
from  that  of  the  foregoing  books:  and  the  solution  of  problems  by  equations 
is  no  longer  the  object,  but  rather  the  demonstration  of  propositions.  There 
appears  no  ground,  beyond  bare  surmise,  to  presume,  that  the  author,  in  the 
rest  of  the  tracts  relative  to  numbers  which  fulfilled  his  promise  of  thirteen 
books,  resumed  the  Algebraic  manner:  or  in  short,  that  the  Algebraic  part 
of  his  performance  is  at  all  mutilated  in  the  copies  extant,  which  are  consi- 
dered to  be  all  transcripts  of  a  single  imperfect  exemplar.  (Bachet  Ep.ad. 
led.) 

It  is  indeed  alleged,  that  the  resolution  of  compound  equations  (two 
species  left  equal  to  one)  which  Diophantus  promises  {Def.  11.)  to  show 
subsequently,  bears  reference  to  a  lost  part  of  his  work.  But  the  author, 
after  confining  himself  to  cases  of  simple  equations  (one  species  equal  to  one 
species)  in  the  first  three  books,  passes  occasionally  to  compound  equations 
(two  species  equal  to  one;  and  even  two  equal  to  two  species;)  in  the  three 
following  books.  Sec  iv.  Q.  33;  vi.  Q.  6  and  19;  and  Bachet  on  Def.  1  J, 
and  i.  Q.  33.  In  various  instances  he  pursues  the  solution  of  the  problem, 
until  he  arrives  at  a  final  quadratic  equation ;  and,  as  in  the  case  of  a  simple 
equation,  he  then  merely  states  the  value  inferrible,  without  specifying  the 


Ixii  NOTES  AND  ILLUSTRATIONS. 

steps  by  which  he  arrives  at  the  inference.  See  iv.  Q.  23;  vi.  Q.  7,  9  and  1 1. 
But,  in  other  places,  the  steps  are  sufliciently  indicated  :  particularly  iv.  Q. 
33  and  45;  v.  Q.  13;  vi.  Q.  24:  and  his  method  of  resolving  the  equation 
is  the  same  with  the  second  of  Brahmkgupta's  rules  for  the  resolution  of 
quadratics  (Brahm.  18.  §  34).  The  first  of  the  Hindu  author's  rules,  the 
same  with  Srid'haua's  quoted  by  Bha'scara  (Vjj.-gan.  §  131.  Brahm.  18. 
§  32.),  differs  from  that  of  Nugnez  (Nonius)  quoted  by  Bachet  (on  Dioph. 
I.  33),  in  dispensing  with  the  preliminary  step  of  reducing  the  square  term 
to  a  single  square:  a  preparation  which  the  Arabs  first  introduced,  as  well 
as  the  distinction  of  three  cases  of  quadratics:  for  it  was  practised  neither 
by  DioPHANTUS,  nor  by  the  Hindu  Algebraists, 

DiopiiANTUs  has  not  been  more  explicit,  nor  methodical,  on  simple,  than 
on  compound,  equations.  But  there  is  no  reason  to  conclude,  that  he  re- 
turned to  either  subject  in  a  latter  part  of  his  work,  for  the  purpose  of  com- 
pleting the  instruction,  or  better  explaining  the  method  of  conducting  the 
resolution  of  those  equations.  Such  does  not  seem  to  be  the  manner  of  his 
arithmetics,  in  which  general  methods  and  comprehensive  rules  are  wanting. 
It  is  rather  to  be  inferred,  as  Cossali  does,  from  the  compendious  way 
in  which  the  principles  of  Algebra  are  delivered,  or  alluded  to,  by  him, 
that  the  determinate  analysis  was  previously  not  unknown  to  the  Greeks ; 
wheresoever  they  got  it:  and  that  Diophantus,  treating  of  it  cursorily  as  a 
matter  already  understood,  gives  all  his  attention  to  cases  of  indeterminate 
analysis,  in  which  perhaps  he  had  no  Greek  precursor.  (Coss.  Orig.  dell' 
Alg.  i.  4.  §  10.)  He  certainly  intimates,  that  some  part  of  what  he  proposes 
to  teach  is  new  :   •crw?  yXv  au  J'oxTi  to  z:^S,yy.x  Siivyi^irt^ov  £7r«iJ»i  juiiVw   y\»ui^ift.ov  Iri. 

While  in  other  places  (Z)e/!  10)  he  expects  the  student  to  be  previousl}'^ 
exercised  in  the  algorithm  of  Algebra.  The  seeming  contradiction  is  recon- 
ciled by  conceiving  the  principles  to  have  been  known  ;  but  the  application 
of  them  to  a  certain  class  of  problems  concerning  numbers  to  have  been 
new. 

Concerning  the  probable  antiquity  of  the  Diophantine  Algebra ;  all  that 
can  be  confidently  affirmed  is,  that  it  is  not  of  later  date  than  the  fourth 
century  of  Christ.  Among  the  works  of  Hvpatia,  who  was  murdered 
A.  D.  41.5,  as  they  are  enumerated  by  Suidas,  is  a  commentary  on  a  work 
of  a  Diophantus,  most  likely  this  author.  An  epigram  in  the  Greek  an- 
thologia  (lib.  2.  c.  22)  is  considered  with  probability  to  relate  to  him :  but 


ARITHMETICS  OF  DIOPHANTUS.  Ixiil 

the  age  of  its  author  Lucillius  is  uncertain.  Bachet  observes,  that,  so  far 
as  can  be  conjectured,  Lucillius  lived  about  the  time  of  Nero.  This, 
however,  is  mere  conjecture. 

DroPHANTUs  is  posterior  to  Hypsicles,  whom  he  cites  in  the  treatise  on 
polygon  numbers.  (Prop,  8.)  This  should  furnish  another  fixt  point.  But 
the  date  of  Hypsicles  is  not  well  determined.  He  is  reckoned  the  author, 
or  at  least  the  reviser,*  of  two  books  subjoined  to  Euclid's  elements,  and 
numbered  14th  and  loth.  In  the  introduction,  he  makes  mention  of  Apol- 
LON'ius,  one  of  whose  writings,  which  touched  on  the  ratio  of  the  dode- 
caedron  and  icosaedron  inscribed  in  the  same  sphere,  was  considered  by 
Basilides  of  Tyre,  and  by  the  father  of  him  (Hypsicles)  as  incorrect,  and 
Wjas  amended  by  them  accordingly  :  but  subsequently  he  (Hypsicles)  met 
with  another  work  of  Apollonius,  in  which  the  investigation  of  the  pro- 
blem was  satisfactory,  and  the  demonstration  of  the  proposition  correct.  Here 
again  Bachet  observes,  that,  so  far  as  can  be  conjectured,  from  the  manner 
in  which  he  speaks  of  Apollonius,  he  must  have  lived  not  long  after  him. 
CossALi  goes  a  little  further;  and  concludes  on  the  same  grounds,  that  they 
were  nearly  contemporary.  {Orig.  delf  Alg.  i.  4.  §  4.)  The  grounds  seem 
inadequate  to  support  any  such  conclusion :  and  all  that  can  be  certainly 
inferred  is,  that  Hypsicles  of  Alexandria  was  posterior  to  Apollonius,  who 
flourished  in  the  reign  of  Ptolomy  Euergetis  :  two  hundred  years  before 
Christ. 

Several  persons  of  the  name  of  Diophantus  are  noticed  by  Greek  authors; 
but  none  whose  place  of  abode,  profession,  or  avocations,  seem  to  indicate 
any  correspondence  with  those  of  the  mathematician  and  Algebraist:  one  a 
prajtor  of  Athens  mentioned  by  Diodokus  Siculus,  Zenobius,  and  Suidas; 
another,  secretary  of  king  Herod,  put  to  death  for  forgery,  as  noticed  by 
Tzetzes;  and  a  third,  the  instructor  of  Libanius  in  eloquence,  named  by 
Suidas  in  the  article  concerning  that  sophist  and  rhetorician. 

The  Armenian  Abu'lfaraj  places  the  Algebraist  Diophantus  under  the 
Emperor  Julian.  But  it  may  be  questioned,  whether  he  has  any  authority 
for  that  date,  besides  the  mention  by  Greek  authors  of  a  learned  person  of 
the  name,  the  instructor  of  Libanius,  who  was  contemporary  with  that 
emperor. 

'  TMkhu'l  hukmd  cited  by  Casivli,  Bibl.  Arab.  Hisp.  i.  346.  The  Arabian  author  uses  the 
word  Asleh  amended. 


Ixiv  NOTES  AND  ILLUSTRATIONS. 

LTpon  the  whole,  however,  it  seems  preferable  to  abide  by  the  date  fur- 
nished in  a  professed  history,  even  an  Arabic  one,  on  a  Grecian  matter :  and 
consider  Diophantus  as  contemporary  with  the  Emperor  Julian,  about 
A.  D.  365.  That  date  is  consistent  with  the  circumstance  of  Hypatia 
writing  a  commentarj'^  on  his  works ;  and  is  not  contradicted  by  any  other 
fact;  nor  by  the  aftirmation  of  any  other  writer  besides  Bombelli  :  on  whose 
authority  Cossali  nevertheless  relies. 

Bombelli,  when  he  announced  to  the  public  the  existence  of  a  manu- 
script of  Diophantus  in  the  Vatican,  placed  the  author  under  the  Emperor 
Antoninus  Pius  without  citing  any  grounds.  His  general  accuracy  is, 
however,  impeached  by  his  assertion,  that  the  Indian  authors  are  frequently 
cited  by  Diophantus.  No  such  quotations  are  found  in  the  very  manu- 
script of  that  author's  work,  which  he  is  known  to  have  consulted :  and 
which  has  been  purposely  reexamined.  (Coss.  i.  4.  §  4.)  Bombelli's 
authority  was,  therefore,  very  properly  rejected  by  Bachet  ;  and  should 
have  been  so  by  Cossali. 


N. 

FROGRESS  AND   PROFICIENCY  OF  THE   ARABIANS  IN 

ALGEBRA. 

In  the  reign  of  the  second  Abbasside  Khalif  Almansu'r,  and  in  the  156th 
year  of  the  Hejira  (_A.  D.  773),  as  is  related  in  the  preface  to  the  Astrono- 
mical tables  of  Ben-Al-Adami  published  by  his  continuator  Alca'sem  in 
SOS  H.  (A.D.  920),  an  Indian  astronomer,  well  versed  in  the  science  which  he 
professed,  visited  the  court  of  the  Khalif,  bringing  with  him  tables  of  the 
equations  of  planets  according  to  the  mean  motions,  with  observations  rela- 
tive to  both  solar  and  lunar  eclipses  and  the  ascension  of  the  signs ;  taken, 
as  he  affirmed,  from  tables  computed  by  an  Indian  prince,  M'hose  name,  as 
the  Arabian  author  writes  it,  was  Phi'ghak.  The  Khalif,  embracing  the 
opportunity  thus  happily  presented  to  him,  commanded  the  Look  to  be 
translated  into  Arabic,  and  to  be  published  for  a  guide  to  the  Arabians  in 
matters  pertaining  to  the  stars.  The  task  devolved  on  Muhammed  ben 
Ibkahi'm  Alfazdri;  whose  version  is  kno^\^l  to  astronomers  by  the  name  of 


ALGEBRA  AMONG  THE  ARABIANS.  Ixv 

tlie  greater  Sind-hind  or  H'utd-sind:  for  the  term  occurs  written  both  ways.' 
It  signifies,  according  to  the  same  author  Bex-al-Adami,  the  revolving 
ages,  Al  dehr  al  ddher;  which  Casiri  translates  perpetuum  aetemumque.* 

No  Sanscrit  term  of  similar  sound  occurs,  bearing  a  signification  recon- 
cilable to  the  Arabic  interpretation.  If  a  conjecture  is  to  be  hazarded,  the 
original  word  may  have  been Sidd'hdnta.  Other  guesses  might  be  proposed: 
partly  combining  sound  with  interpretation,  and  taking  for  a  termination 
sind'hu  ocean,  which  occurs  in  titles  now  familiar  for  works  relative  to  the 
regulation  of  time,  as  Cdla-sind'hu,  Samaya-sind'hu,  &c.  or  adhering  exclu- 
sively to  sound,  as  Indu-sindliu,  or  Jndu-siddhdnta;  the  last  a  title  of  the 
same  import  with  Suma-siddhdnta  still  current.  But  whatever  may  have 
been  the  name,  the  system  of  astronomy,  which  was  made  known  to  the 
Arabs,  and  which  is  by  them  distinguished  by  the  appellation  in  question, 
appears  to  have  been  that  which  is  contained  in  the  Brahma-sidd'hdnta,  and 
which  is  taught  in  Brahmeglpta's  revision  of  it.  This  fact  is  deducible 
from  the  number  of  elapsed  da3s  between  the  beginning  of  planetary  mo- 
tions and  the  commencement  of  the  present  age  of  the  world,  according  to 
the  Indian  reckoning,  as  it  is  quoted  by  the  astrologer  of  Balkh  Abu-mashar, 
and  which  precisely  agrees  with  Brahmegupta.  The  astrologer  does  not 
indeed  specify  which  of  the  Indian  systems  he  is  citing.  But  it  is  distinctly 
affirmed  by  later  Arabian  authorities,  that  only  one  of  the  three  Indian  doc- 
trines of  astronomy  was  understood  by  the  Arabs ;  and  that  they  had  no 
knowledge  of  the  other  two  beyond  their  names.'  Besides,  Arvabhatta 
and  the  Arca-sidd'/idnta,  the  two  in  question,  would  have  furnished  very 
different  numbers. 

Tlic  passage  of  Abu-mashar,  to  which  reference  has  been  now  made,  is 
remarkable,  and  even  important ;  and,  as  it  has  been  singularly  misunder- 
stood and  grossly  misquoted  by  Baillt  in  his  Astronomic  Ancieune  (p.  302), 
it  may  be  necessary  to  cite  it  at  full  length  in  this  place.  It  occurs  at  the 
end  of  the  fourth  tract  (and  not,  as  Bailly  quotes,  the  beginning  of  the 
fifth,)  in  Abu-mashar's  work  on  the  conjunctions  of  planets.  The  author 
there  observes,  that  "  the  Indians  reckoned  the  beginning  [of  the  world]  on 

'  Bai.  ^rab.  Hisp.  citing  Bibl.  Arab.  Vhil  (Tdr'ikhu'l  huhn/i)  i.  428.  voce  Alphaz6ri. 
*  Ibid.  i.  4.26.  voce  Katka.     Sind  and  Hmd  likewise  signify,  in  the  Arabian  wrilers,  the  hither 
«nd  remoter  India.     D'Herbelot.  Bibi.  Orient.  415. 

'  T&rikki/l  hukmA,  cited  by  CASiar,  Bibl.  Arab.  Hisp.  i.  426.  voce  Katka. 

k 


Ixvi  NOTES  AND  ILLUSTRATIONS. 

"  Sunday  at  sunrise  (or,  to  quote  from  the  Latin  version,  Et  estimavcrunt 
"  Indi  quod  principium  fuit  die  dominica  sole  ascendente;)  and  between  that 
"  day  and  the  day  of  the  deluge  (et  est  inter  eos,  s.  inter  ilium  diem  et  ilium 
"  diem  diluvii)  720634442715  days  equivalent  to  1900340938*  Persian  years 
"  and  344  days.  The  deluge  happened  on  Friday  (et  fuit  diluvium  die 
"  veneris)  27th  day  of  Rabe  1st,  which  is  29  from  Cibat  and  14  from  Adris- 
"  tinich.  Between  the  deluge  and  the  first  day  of  the  year  in  which  the 
"  Hejira  occurred  (fuerunt  ergo  inter  diluvium  et  prinium  diem  anni  in 
"  quo  fuit  Alhegira)  3837  years  and  268  days;  which  will  be,  according  to 
"  the  years  of  tlie  Persians,  3725  years  and  348  days.  And  between  the 
"  deluge  and  the  day  of  Jesdagir  (Yezdajerd)  king  of  the  Persians,  from 

"  the  beginning  of  whose  reign  the  Persians  took  their  era, 3735  years, 

"  10  months,  and  22  days."  The  author  proceeds  with  the  comparison  of 
the  eras  of  the  Persians  and  Arabians,  and  those  of  Alexaxdeii  and  Phi- 
tiv ;  and  then  concludes  the  treatise :  completi  sunt  quatuor  tractatus,  deo 
adjuvante. 

Bailly's  reference  to  this  passage  is  in  the  following  words.  "  Albu- 
"  MASAR*  rapporte  que  selon  les  Indiens,  il  s'est  6coul6  720634442715  jours 
"  entre  le  deluge  et  T^poque  de  I'hegire.  II  en  coiiclud,  on  ne  sait  trop  com- 
"  ment,  qu'il  s'est  6coul6  3725  ans  dans  cet  intervalle :  ce  qui  placeroit  le 
"  deluge  3103  ans  avant  J,  C.  pr^cisement  <\,  I'^poque  chronologique  et  astro- 
'•  nomique  des  Indiens.  Mais  Albumasar  ne  dit  point  comment  il  est 
"  parvenu  k  6galcr  ces  deux  nombres  de  3725  ans  et  de  720634442715  jours." 
Ast.  anc.  eel.  liv.  i.  §  xvii. 

Now  on  this  it  is  to  be  observed,  that  Bailly  makes  the  antediluvian 
period  between  the  Sunday  on  which  the  world  began  and  the  Friday  on 
which  the  deluge  took  place,  comprising  720634442715  days,  to  be  the  same 
with  the  postdiluvian  period,  from  the  deluge  to  the  Hejira ;  and  that  he 
quotes  the  author,  as  unaccountably  rendering  that  number  equivalent  to 
.'3725  years,  though  the  text  expressly  states  more  than  igoOOOOOOO  years. 
The  blunder  is  the  more  inexcusable,  as  Bailly  himself  remarked  the  in- 
consistency, and  should  therefore  have  reexamined  the  text  which  he  cited, 
to  verify  his  quotation. 

*  There  is  something  wanting  in  the  number  of  years:  which  is  deficient  at  the  third  pl.ice. 
Both  editions  of  the  translation  (Augsburg  1489,  Venice  1515)  give  the  same  words. 
'  De  Magn.  Conj.  Traite  v,  au  commencement. 


ALGEBRA  AMONG  THE  ARABIANS.  Ixvii 

Major  "WiLFORD  (As.  Res.  10.  ll?-)?  relying  on  the  correctness  of 
Bailly's  quotation,  concluded,  that  the  error  originated  with  either  the 
transcriber  or  translator.  But  in  fact  the  mistake  rested  solely  with  the 
citer:  as  he  would  have  found  if  his  attention  had  been  drawn  to  the  more 
correct  quotation  in  Anquetil  du  Perron's  letter  prefixed  to  his  Rech. 
Hist,  et  Geog.  sur  rinde,  inserted  in  Bernoulli's  2d  vol.  of  Desc.  de  rinde 
(p.  xx).  But,  though  Anquetil  is  more  accurate  than  Bailly  in  quota- 
tion, he  is  not  more  successful  in  his  inferences,  guesses  and  surmises.  For 
he  strangely  concludes  from  a  passage,  which  distinctly  proves  the  use  of 
the  great  cycle  of  the  culpa  by  the  Indian  astronomers  to  whom  Abu- 
MASHAR  refers,  that  they  were  on  the  contrary  unacquainted  in  those  days 
with  a  less  cycle,  which  is  comprehended  in  it.  So  little  did  he  understand 
the  Indian  periods,  that  he  infers  from  a  specified  number  of  elapsed  days 
and  correspondent  years,  reckoned  from  the  beginning  of  the  great  cycle 
which  dates  from  the  supposed  moment  of  the  commencement  of  the  world, 
that  they  knew  nothing  of  a  subordinate  period,  which  is  one  of  the  ele- 
ments of  that  cycle.  Nor  is  he  nearer  the  truth,  but  errs  as  much  the  other 
way,  in  his  conjecture,  that  the  number  of  solar  years  stated  by  Abu- 
MASHAR  relates  to  the  duration  of  a  life  of  Brahma,  comprising  a  hundred 
of  that  deity's  years. 

In  short,  Anquetil's  conclusions  are  as  erroneous  as  Bailly's  premises. 
The  discernment  of  Mr.  Davis,  to  whom  the  passage  was  iiidicated  by 
Major  WiLFOKD,  anticipated  the  correction  of  this  blunder  of  Bailly,  by 
restoring  the  text  with  a  conjectural  emendation  worthy  of  his  sag-acity.' 

The  name  of  the  Indian  author,  from  whom  Abumashar  derived  the 
particulars  which  he  has  furnished,  is  written  by  Bailly,  Kankaraf;  taken, 
as  he  says,  from  an  ancient  Arabic  writer,  whose  work  is  subjoined  to  that 
of  Messala  published  at  Nuremberg  by  Joach.  Heller  in  1648."  The 
Latin  translation  of  Messahala  (Ma-sha'a-Allah)  was  edited  by  Joachim 
Heller  at  Nuremberg  in  1549;  but  it  is  not  followed,  in  the  only  copy 
accessible  to  me,  by  the  work  of  any  other  Arabic  author;  and  the  quotation 
consequently  has  not  been  verified.  D'Herbelot  writes  the  name  vari- 
ously; Kankah  ox  Cancah,  Kenker  ox  Kankar,  and  Ketighek  ox  Kanghah ;^ 

'  As.  Res.  9.  242.     Appendix  to  an  Essay  of  Major  Wilford. 

*  Ast.  Anc.  303. 

'  Bibl.  Or.  Art.  Cancah  al  Hendi,  and  Kenker  al  Hendi.    Also  Ketab  Menazel  al  Caraar  and 

Ketab  al  Keranat. 

k2 


Ixviii  NOTES  AND  ILLUSTRATIONS. 

to  which  Reiske  and  Schultens,  from  further  research,  add  another  varia- 
tion, iifeng-c//;*  which  is  not  of  Arabic  but  Persian  orthography.  Casiri, 
by  a  diflFerence  of  the  diacritical  point,  reads  from  the  Tarikhul  hukma, 
and  transcribes,  Katka.'  That  the  same  individual  is  all  along  meant, 
clearly  appears  from  the  correspondence  of  the  works  ascribed  to  him; 
especially  his  treatise  on  the  greater  and  less  conjunctions  of  the  planets, 
which  was  imitated  by  Abu-mashar. 

Amidst  so  much  diversity  in  the  orthography  of  the  word  it  is  difficult 
to  retrieve  the  original  name,  without  too  much  indulgence  in  conjecture. 
Canca,  Avhich  comes  nearest  to  the  Arabic  corruption,  is  in  Sanscrit  a  proper 
name  among  other  significations :  but  it  does  not  occur  as  the  appellation  of 
any  noted  astrologer  among  the  Hindus.  Garga  does;  and,  as  the  Arabs 
have  not  the  soft  guttural  consonant,  they  must  widely  corrupt  that  sound: 
yet  Catighar  and  Cancah  seem  too  remote  from  it  to  allow  it  to  be  proposed 
as  a  conjectural  restoration  of  the  Indian  name. 

•  To  return  to  the  more  immediate  subject  of  this  note.  The  work  of 
Alfazari,  taken  from  the  Hindu  astronomy,  continued  to  be  in  general  use 
among  the  Muhammedans,  until  the  time  of  Alma'mu'n  ;  for  whom  it  was 
epitomized  by  Muhamjied  ben  Musa  Al  Khuxvarezmi;  and  his  abridgment 
was  thenceforward  known  by  the  title  of  the  less  Sind-hind.  It  appears  to 
have  been  executed  for  the  satisfaction  of  Aljia'mu'n  before  this  prince's  ac- 
cession to  the  Khelafet,  which  took  place  early  in  the  third  century  of  the 
Ilejira  and  ninth  of  Christ.  The  same  author  compiled  similar  astronomical 
tables  of  his  own ;  wherein  he  professed  to  amend  the  Indian  tables  which 
furnished  the  mean  motions ;  and  he  is  said  to  have  taken,  for  that  purpose, 
equations  from  the  Persian  astronomy ;  some  other  matters  from  Ptolomy  ; 
and  to  have  added  something  of  his  own  on  certain  points.  His  work  is 
reported  to  have  been  well  received  by  both  Hindus  and  Muhammedans: 
and  the  greater  tables,  of  which  the  compilation  was  commenced  in  the  fol- 
lowing age  by  Bex  al  adami  and  completed  by  Al  Casem,  were  raised 
upon  the  like  foundation  of  Indian  astronomy  :  and  were  long  in  general  use 
among  the  Arabs,  and  by  them  deemed  excellent.  Another  and  earlier  set 
of  astronomical  tables,  founded  on  the  Indian  system  called  Sind-hind,  was 
compiled  by  Habash  an  astronomer  of  Baghdad;  who  flourished  in  the 

'  Bibl.  Or.  (1777-79)-  iv.  725.    Should  be  Kengeh:  a  like  error  occurs  in  p.  727,  where  iharch 
is  put  for  thareh. 
'  Bibl.  Arab.  Hisp.  i.  426. 


ALGEBRA  AMONG  THE  ARABIANS.  .   Ixix 

time  of  the  Khalif  Alma'mux.'  Several  others,  similarly  founded  on  the 
mean  motions  furnished  by  the  same  Indian  system,  were  published  in  the 
third  century  of  Hejira  or  earlier:  particularly  those  of  Fazl  ben  Hatim 
Narizi;  and  Al  Hasan  ben  ^Misbah.* 

It  was  no  doubt  at  the  same  period,  while  the  Arabs  were  gaining  a 
knowledge  of  one  of  the  Indian  systems  of  Astronomy,  that  they  became 
apprized  of  the  existence  of  two  others.  No  intimation  at  least  occurs  of 
any  different  specific  time  or  more  probable  period,  when  the  information 
was  likely  to  be  obtained  by  them ;  than  that  in  which  they  were  busy  with 
the  Indian  astronomy  according  to  one  of  the  three  systems  that  prevailed 
among  the  Hindus:  as  the  author  of  the  Tarikhul  hukmd  quoted  by 
Casiri  affirms.  This  writer,  whose  compilation  is  of  the  twelfth  century,' 
observes,  that  '  owing  to  the  distance  of  countries  and  impediments  to 
'  intercourse,  scarcely  any  of  the  writings  of  the  Hindus  had  reached  the 
'  Arabians.  There  are  reckoned,  he  adds,  three  celebrated  systems  (Mazhab) 
'  of  astronomy  among  them ;  namely,  Sind  and  kind;  Arjabahar,  and  Ar- 
'  cand:  one  only  of  which  has  been  brought  to  us,  namely,  the  Sind-hind: 
'  which  most  of  the  learned  Muhammedans  have  followed.'  After  naming 
the  authors  of  astronomical  tables  founded  on  that  basis,  and  assigning  the 
interpretation  of  the  Indian  title,  and  quoting  the  authority  of  Bex  al  adami, 
the  compiler  of  the  latest  of  those  tables  mentioned  by  him,  he  goes  on  to 
say,  that  '  of  the  Indian  sciences  no  other  communications  have  been  re- 
'  ceived  by  us  (Arabs)  but  a  treatise  on  music  of  which  the  title  in  Hindi  is 
'  Biydphar,  and  the  signification  of  that  title  "  fruit  of  knowledge;"*  the 

*  work  entitled  Cal'dah  and  Damanah,  upon  ethics:  and  a  book  of  numerical 

*  computation,  which  Abu  Jafr  Muhammed  ben  Musa  Al  Khuwdrezmi 
'  amplified  (hasat)  and  which  is  a  most  expeditious  and  concise  method,  and 
'  testifies  the  ingenuity  and  acuteness  of  the  Hindus.' ' 

The  book,  here  noticed  as  a  treatise  on  ethics,  is  the  well-known  collection 
of  fables  of  Filpai  or  Bidpai  (Sans.  Vaidyapriya) ;  and  was  translated  from 

'  T<fnA^u7  AuA7»({,  Casiri,  i.  426  and  428.     Abulfaraj;  Pococke  161. 

*  lb.  i.42l  and  413. 

■^  He  flourished  in  595  H.  (A.  D.  lips),  as  appears  from  passages  of  Iiis  work,  M.S. 
MDCCLXXIII.  Lib.  Esc.  p.  74  and  3l6.     Canri,  ii.  332. 

*  Sans.  Vidy/iphala,  fruit  of  science. 

'  Casiri,  i.  426  and  428.  The  Cashful  zanun  specifies  three  astronomical  systems  of  the 
Hindus  under  the  same  names. 


\xx  NOTES  AND  ILLUSTRATIONS. 

the  Pehlevi  version  into  Arabic,  by  command  of  the  same  Abbaside  Khaltf 
Almansu'r,*  who  caused  an  Indian  Astronomical  treatise  to  be  translated 
into  the  Arabian  tongue.  The  Arabs,  however,  had  other  communications 
of  portions  of  Indian  science,  which  the  author  of  the  Tarikhul  hukmd  has 
in  this  place  overlooked:  especially  upon  medicine,  on  which  many  trea- 
tises, general  and  particular,  were  translated  from  the  Indian  tougue.  For 
instance,  a  tract  upon  poisons  by  Shanac,  (Sansc.  Characa?)  of  which  an 
Arabic  version  was  made  for  the  Khalif  Alma'mu'n,  by  his  preceptor  Abbas 
ben  SAfD  Jdhari.  Also  a  treatise  on  medicine  and  on  materia  medica  in 
particular,  which  bears  the  name  of  Shashurd  (Sansc.  Susruta);  and  nu- 
merous others." 

The  Khuwarezmite  Muhammed  ben  Musa,  who  is  named  as  having 
made  known  to  the  Arabians  the  Indian  method  of  computation,  is  the  same 
"who  is  recognized  by  Arabian  authors  with  almost  a  common  consent  (Zaca- 
hia  of  Casbin,  &c.)  as  the  first  who  wrote  upon  Algebra.  His  competitor  for 
the  honour  of  priority  is  Abu  Ka'mil  Shujaa  ben  Aslam,  surnamed  the 
Egyptian  arithmetician,  (Hasib  al  Misri,)  ;  whose  treatise  on  Algebra  was 
commented  by  Ali  ben  Ahmed  Al  AmrAni  of  Musella;^  and  who  is  said  by 
D'Herbelot  to  have  been  the  first  among  learned  Muslemans,  that  wrote 
upon  this  branch  of  mathematics.*  The  commentator  is  a  writer  of  the  tenth 
century;  the  date  of  his  decease  being  recorded  as  of  344  H.'  (A.  D.  955.) 
The  age,  in  which  his  author  flourished,  or  the  date  of  his  text,  is  not  fur- 
nished by  any  authority  which  has  been  consulted :  and  unless  some  evidence 
be  found,  showing  that  he  was  anterior  to  the  Khuwarezfni,  we  may 
abide  by  the  historical  authority  of  Zacarta  of  Casbin;  and  consider  the 
Khuwdrezmi  as  the  earliest  writer  on  Algebra  in  Arabic.  Next  was  the 
celebrated  Alchindus  (Abu  Yusef  Alkendi)  contemporary  with  the  astro- 
loger Abu-masher  in  the  third  century  of  the  Hejira  and  ninth  of  the 
Christian  era,*  an  illustrious  philosopher  versed  in  the  sciences  of  Greece,  of 

•  Introd.  llem.  Hitopadtsa.     Sansc.  ed.  1804. 

*  D'Hekbelot,  Bibl.  Orient.  Ketab  al  saraoun,  Ketab  Sendhascbat,  Ketab  al  sokkar,  Ketab 
Schaschourd  al  Hendi,  Kftab  Rai  al  Hendi,  Ketab  Noufschal  al  Hendi,  Ketab  al  akakir,  &c. 

*  Tdrikhu'l  hukmd,  Casiui,  i.  410. 

♦  Bibl.  Orient.  482.  Also  226  and  494.  No  grounds  are  specified.  Eev  Khalca'n  and 
Ha'ji  Kiialfah,  whom  he  very  commonly  follows,  have  been  searched  in  vain  for  authority  on 
this  point. 

»  Tdr.  Casiri,  i.  410.  •  Abvlfaraj;  Pococke,  179. 


ALGEBRA  AMONG  THE  ARABIANS.  Ixxi 

India,  and  of  Persia,  and  author  of  several  treatises  upon  numbers.  In  the 
prodigious  multitude  of  his  writings  upon  every  branch  of  science,  one  is 
specified  as  a  tract  on  Indian  computation  (Hisabul  hindi):  others  occur 
with  titles  which  are  understood  by  Casiri  to  relate  to  Algebra,  and  to  the 
'  finding  of  hidden  numbers :'  but  which  seem  rather  to  appertain  to  other 
topics.*  It  is,  however,  presumable,  that  one  of  the  works  composed  by 
him  did  treat  of  Algebra  as  a  branch  of  the  science  of  computation.  His 
pupil  Ahmed  ben  ]\Iuhammed  of  Sarkhasi  in  Persia,  (who  flourished  in  the 
middle  of  the  third  century  of  the  Hejira,  for  he  died  in  286  H.)  was  author 
of  a  complete  treatise  of  computation  embracing  Algebra  with  Arithmetic. 
About  the  same  time  a  treatise  of  Algebra  was  composed  by  Abu  Hanifah 
Daindwari,  who  lived  till  290  H.  (A.  D.  c)03.) 

At  a  later  period  Abu'lwafa'  Biizjdni,  a  distinguished  mathematician,  who 
flourished  in  the  fourth  century  of  the  Hejira,  between  the  years  348  when 
he  commenced  his  studies,  and  388  the  date  of  his  demise,  composed  nume- 
rous tracts  on  computation,  among  which  are  specified  several  commentaries 
on  Algebra:  One  of  them  on  the  treatise  of  the  Khuwarezmite  upon  that  sub- 
ject :  another  on  a  less  noted  treatise  by  Abu  Yahya,  whose  lectures  he  had 
attended :  an  interpretation  (whether  commentary  or  paraphrase  may  per- 
haps be  doubted)  of  the  work  of  Diophantus  :  demonstrations  of  the  pro- 
positions contained  in  that  work :  a  treatise  on  numerical  computation  in 
general:    and  several  tracts  on  particular  branches  of  this  subject." 

A  question  has  been  raised,  as  just  now  hinted,  whether  this  writer's  inter- 
pretation of  Diophantus  is  to  be  deemed  a  translation  or  a  commentary. 
The  term,  which  is  here  employed  in  the  Tdrikhul  hukmd,  (Jafsir,  para- 
phrase,) and  that  which  Abulfaraj  uses  upon  the  same  occasion  (fasr, 
interpreted,)  are  ambiguous.  Applied  to  the  relation  between  works  in  the 
same  language,  the  term,  no  doubt,  implies  a  gloss  or  comment;  and  is  so 
understood  in  the  very  same  passage  where  an  interpretation  of  the  Khu- 
warezmite's  treatise,  and  another  of  Abu  Yahva's,  were  spoken  of.  But, 
where  a  difference  of  language  subsists,  it  seems  rather  to  intend  a  ver- 
sion, or  at  least  a  paraphrase,  than  mere  scholia ;  and  is  employed  by  the 
same  author  in  a  passage  before  cited,'  where  he  gives  the  Arabic  sig- 
nification of  a  Hindi  term.     That  Buzjdnis,  performance  is  to  be  deemed  a 

•  Tdrikhu'l hukmd  ;  Casihi,  i,  353—360.  *  lb,  i.  433.  '  lb.  i.  426.  Art.  Katka. 


Ixxii  NOTES  AND  ILLUSTRATIONS. 

translation,  appears  to  be  fairly  inferrible  from  the  separate  mention  of  the 
demonstration  of  the  propositions  in  Dioph  antus,  as  a  distinct  work  :  for  the 
latter  seems  to  be  of  the  nature  of  a  commentary  ;  and  the  other  consequently 
is  the  more  likely  to  have  been  a  version,  whether  literal  or  partaking  of 
paraphrase.  Besides,  there  is  no  mention,  by  any  Arabian  writer,  of  an 
earlier  Arabic  translation  of  Diopii antus;  and  the  Buzj&ni  was  not  likely  to 
be  the  commentator  in  Arabic  of  an  untranslated  Greek  book.  D'Herbelot 
then  may  be  deemed  correct  in  naming  him  as  the  translator  of  the  Arithme- 
tics of  DioPHANTUs;  and  Cossali,  examining  a  like  question,  arrives  at 
nearly  the  same  conclusion;  namely,  that  the  Buzjdni  was  the  translator, 
and  the  earliest,  as  well  as  the  expositor,  of  Diophantus. — (Orig.  deW  Alg. 
i.  175.)  The  version  was  probably  made  soon  after  the  date,  which  Abul- 
FARAJ  assigns  to  it,  348  H.  (A.  D.  969),  which  more  properly  is  the  date  of 
the  commencement  of  the  translator's  mathematical  studies. 

From  all  these  facts,  joined  with  other  circumstances  to  be  noticed  in  pro- 
gress of  this  note,  it  is  inferred,  1st,  that  the  acquaintance  of  the  Arabs  with 
the  Hindu  astronomy  is  traced  to  the  middle  of  the  second  century  of  the 
Plejira,  in  the  reign  of  Almansur;  upon  authority  of  Arabian  historians 
citing  that  of  the  preface  of  ancient  astronomical  tables :  while  their  know- 
ledge of  the  Greek  astronomy  does  not  appear  to  have  commenced  until  the 
subsequent  reign  of  Ha'run  Alrashid,  when  a  translation  of  the  Almagest 
is  said  to  have  been  executed  under  the  auspices  of  the  Barmacide  Yahya 
ben  Kha'led,  by  Aba  hia'n  and  Salama  employed  for  the  purpose.'  2dly, 
That  they  were  become  conversant,  in  the  Indian  method  of  numerical  com- 
putation, within  the  second  century;  that  is,  before  the  beginning  of  the 
reign  of  Alma'mu'n,  whose  accession  to  the  Khelafet  took  place  in  205  H. 
3dly,  That  the  first  treatise  on  Algebra  in  Arabic  was  published  in  his  reign ; 
but  their  acquaintance  with  the  work  of  Diophantus  is  not  traced  by  any 
historical  facts  collected  from  their  writings  to  a  period  anterior  to  the  middle 
of  the  fourth  century  of  the  Hejira,  when  Abu'lwafa'  Buzjdni  flourished. 
4thly,  That  Muhammed  ben  Musa  Khuwdrezmi,  the  same  Arabic  author, 
who,  in  the  time  of  Alma'mu'n,  and  before  his  accession,  abridged  an  earlier 
astronomical  work  taken  from  the  Hindus,  and  who  published  a  treatise  on 
the  Indian  method  of  numerical  computation,  is  the  first  also  who  furnished 

^  •  Casiai,  i.  349. 


ALGEBRA  AMONG  THE  ARABIANS.      ,  Ixxiii 

the  Arabs  with  a  knowledge  of  Algebra,  upon  which  he  expressly  wrote,  and 
in  that  Khalif  s  reign :  as  will  be  more  particularly  shown,  as  we  proceed. 

A  treatise  of  Algebra  bearing  his  name,  it  may  be  here  remarked,  was  in 
the  hands  of  the  Italian  Algebraists,  translated  into  the  Italian  language, 
not  very  long  after  the  introduction  of  the  science  into  that  country  by 
Leonardo  of  Pisa.  It  appears  to  have  been  seen  at  a  later  period  both  by 
Cardan  and  by  BoiMBELLi.  No  manuscript  of  that  version  is,  however, 
now  extant;  or  at  least  known  to  be  so. 

Fortunately  a  copy  of  the  Arabic  original  is  preserved  in  the  Bodleian 
collection.  It  is  the  manuscript  marked  CMXVIII  Hunt.  £14.  fo.  and 
bearing  the  date  of  the  transcription  743  H.  (A.  D.  1342.)  The  rules  of 
the  library,  though  access  be  readily  allowed,  preclude  the  study  of  any 
book  which  it  contains,  by  a  person  not  enured  to  the  temperature  of  apart- 
ments unvisited  by  artificial  warmth.  This  impediment  to  the  examination 
of  the  manuscript  in  question  has  been  remedied  by  the  assistance  of  the 
under  librarian  Mr.  Alexander  Nicoll;  who  has  furnished  ample  extracts 
purposely  transcribed  by  him  from  the  manuscript.  This  has  made  it  practi- 
cable to  ascertain  the  contents  of  the  book,  and  to  identify  the  work  as  that 
in  which  the  Khivwarezmi  taught  the  principles  of  Algebra;  and  conse- 
quently to  compare  the  state  of  the  science,  as  it  was  by  him  taught,  with  its 
utmost  progress  in  the  hands  of  the  Muhammedans,  as  exhibited  in  an  ele- 
mentary work  of  not  very  ancient  date,  which  is  to  this  time  studied  among 
Asiatic  Muslcmans. 

I  allude  to  the  Khuldsetn'l  hisah  of  Behau'ldin;  an  author,  who  lived 
between  the  years  9-53  and  1031  H.  The  Arabic  text,  with  a  Persian  com- 
mentary, has  been  printed  in  Calcutta;  and  a  summary  of  its  contents  had 
been  previously  given  by  Mr.  Strachey  in  his  "  Early  History  of  Algebra," 
in  which,  as  in  his  other  exertions  for  the  investigation  of  Hindu  and  Ara- 
bian Algebra,  his  zeal  surmounted  great  difficulties ;  while  his  labours  have 
thrown  much  light  upon  the  subject.' 

The  title  page  of  the  manuscript  above  described,  as  well  as  a  marginal 
note  on  it,  and  the  author's  preface,  all  concur  in  declaring  it  the  work  of 
MuHAMMED  ben  MusA  Khuwdrezmi :  and  the  mention  of  the  Khabf  Alma- 


•  ^ee  Bija  Ganita,  or  Algebra  of  the  Hindus;  London,  1813.     Hutton's  Math.   Diet.  Ed. 
1815.  Art.  Algebra:  and  As.  Res.  12.  159- 

I 


Ixxiv  NOTES  AND  ILLUSTRATIONS. 

MUX  in  that  preface,  establishes  the  identity  of  the  author,  whose  various 
works,  as  is  learned  from  Arabian  historians,  were  composed  by  command,  or 
with  encouragement,  of  that  Khalif,  partly  before  his  accession,  and  partly 
during  his  reign. 

The  preface,  a  transcript  of  which  was  supplied  by  the  care  of  Mr. 
NicoLL,  has  been  examined  at  my  recjuest,  by  Colonel  John  Baillte. 
After  perusing  it  with  him,  I  am  enabled  to  atlirm,  that  it  intimates  "  en- 
couragement from  the  Imam  Almamu'n  Commander  of  the  Faithful,  to 
compile  a  compendious  treatise  of  calculation  by  Algebra;"  terms,  which 
amount  not  only  to  a  disclaimer  of  any  pretensions  to  the  invention  of  the 
Algebraic  art;  but  which  would  to  my  apprehension,  as  to  that  of  the  distin- 
guished Arabic  scholar  consulted,  strongly  convey  the  idea  of  the  pre- 
existeuce  of  ampler  treatises  upon  Algebra  in  the  same  language  (Arabic), 
did  not  the  marginal  note  above  cited  distinctly  assert  this  to  be  "  the  first 
treatise  composed  upon  Algebra  among  the  faithful;"  an  assertion  corrobo- 
rated by  the  similar  affirmation  of  Zacaria  of  Casbin,  and  other  writers 
of  Arabian  history.  Adverting,  however,  to  that  express  affirmation,  the 
author  must  be  here  understood  as  declaring  that  he  compiled  (alaj' is  the 
verb  used  by  him)  the  treatise  upon  Algebra  from  books  in  some  other  lan- 
guage: doubtless  then  in  the  Indian  tongue;  as  it  has  been  already  shown, 
that  he  was  conversant  with  Hindu  astronomy,  and  Hinducomputation  and 
account.   ,.:::;    i       ;■  . 

It  may  be  right  to  notice,  that  the  title  of  the  manuscript  denominates  the 
author  "  Abu  abdullah  Muiiammed  ben  Musa  al  Khuwdrezmi,  differ- 
ing in  the  first  part  of  the  name  from  the  designation,  which  occurs  in  one 
passage  of  the  Tdrikhul  hukmd,  quoted  by  Casiri,  where  the  Khuwdrezmi 
MuHAMMED  ben  Musa  is  called  Abu-jafr.^  But  that  is  not  a  sufficient 
ground  for  questioning  the  sameness  of  persons  and  genuineness  of  the 
work,  as  the  Khuxcdrezmi  is  not  usually  designated  by  cither  of  those  addi- 
tions, or  by  any  other  of  that  nature  taken  from  the  name  of  offspring:  and 
error  may  be  presumed ;  most  probably  on  the  part  of  the  Egyptian  author 
of  the  Tdrikhul  hukmd,  since  the  addition,  which  he  introtluces,  that  of 
Abu-jafr,  belongs  to  IMuhammed  ben  Musa  ben  Shaker,  a  very  different 
person;  as  appears  from  another  passage  of  the  same  Egyptian's  compilation." 

•  Casiri,  i.  428.  '  Casiri,!.  418. 


ALGEBIL'^  AMONG  TPIE  ARABIANS.  Ixxr 

The  following  is  a  translation  of  the  Khuwdrezmts  directions  for  the  solu- 
tion of  equations :  simple  and  compound:  atopic,  which  he  enters  upon  at  no 
great  distance  from  the  commencement  of  the  volume:  having  first  treated 
of  unity  and  number  in  general. 

'  I  found,  that  the  numbers,  of  which  there  is  need  in  computation  by 
restoration  and  comparison,'  are  of  three  kinds;  namely,  roots  and  squares, 
and  simple  number  relative  to  neither  root  nor  square.  A  root  is  the  whole 
of  thing  multiplied  by  [root]  itself,  consisting  of  unity,  or  numbers  ascending, 
or  fractions  descending.  A  square  is  the  whole  amount  of  root  multiplied  into 
itself  And  simple  number  is  the  whole  that  is  denominated  by  the  number 
without  reference  to  root  or  square. 

'  Of  these  three  kinds,  which  are  equal,  some  to  some,  the  cases  are  these  : 
for  instance,  you  say  "  squares  are  equal  to  roots;"  and  "  squares  are  equal  to 
numbers;"  and  "  roots  are  equal  to  numbers." 

'  As  to  the  case  in  which  squares  are  equal  to  roots;  for  example,  "  a  square 
is  equal  to  five  roots  of  the  same:"  the  root  of  the  square  is  five;  and  the 
square  is  twenty-five:  and  that  is  equivalent  to  five  times  its  root. 

'  So  you  say  "  a  third  of  the  square  is  equal  to  four  roots:"  the  whole 
square  then  is  equal  to  twelve  roots;  and  that  is  a  hundred  and  forty-four; 
its  root  is  twelve. 

'  Another  example :  you  say  "  five  squares  are  equal  to  ten  roots."  Then 
one  square  is  equal  to  two  roots:  and  the  root  of  the  square  is  two;  and  the 
square  is  four. 

'  In  like  manner,  whether  the  squares  be  many  or  few,  they  are  reduced  to 
a  single  square  :  and  as  much  is  done  to  the  equivalent  in  roots ;  reducing  it 
to  the  like  of  that  to  which  the  square  has  been  brought. 

*  Case  in  which  squares  are  equal  to  numbers:  for  instance,  you  say,  "  the 
square  is  equal  to  nine."  Then  that  is  the  square,  and  the  root  is  three. 
And  you  say  "  five  squares  are  equal  to  eighty :"  then  one  square  is  a  fifth  of 
eighty;  and  that  is  sixteen.  And,  if  you  say,  "  the  half  of  the  square  is 
equal  to  eighteen:"  then  the  square  is  equal  to  thirty-six;  and  its  root  is  six. 

'  In  like  manner,  with  all  squares  affirmative  and  negative,  you  reduce 
them  to  a  single  square.  If  there  be  less  than  a  square,  you  add  thereto, 
until  the  square  be  quite  complete.  Do  as  much  with  the  equivalent  in 
numbers, 

*  Hisdbi^ljebr  iva  al  mukibahk. 
12 


Ixxvi  NOTES  AND  ILLUSTRATIONS, 

'  Case  in  which  roots  are  equal  to  number:  for  instance,  you  say  "  the  root 
equals  three  in  number."  Then  the  root  is  three;  and  the  square,  which  is 
raised  therefrom,  is  nine.  And,  if  you  say  "  four  roots  are  equal  to  twenty;" 
then  a  single  root  is  equal  to  five;  and  the  square,  that  is  raised  tl)erefrom,  is 
twenty-five.  And,  if  you  say  "  the  half  of  the  root  is  equal  to  ten;"  then  the 
[whole]  root  is  equal  to  twenty  ;  and  the  square,  which  is  raised  therefrom,  is 
four  hundred. 

'  I  found,  that,  with  these  three  kinds,  namely,  roots,  squares,  and  number 
compound,  there  will  be  three  compound  sorts  [of  equation];  that  is,  squares 
and  roots  equal  to  number ;  squares  and  number  equal  to  roots ;  and  roots 
and  number  equal  to  squares. 

'  As  for  squares  and  roots,  which  are  equal  to  number:  for  example,  you 
say  "  square,  and  ten  roots  of  the  same,  amount  to  the  sum  of  thirty-nine." 
Then  the  solution  of  it  is :  you  halve  the  roots ;  and  that  in  the  present 
instance  yields  five.  Then  you  multiply  this  by  its  like,  and  the  product  is 
twenty-five.  Add  this  to  thirty-nine:  the  sum  is  sixty-four.  Then  take 
the  root  of  this,  which  is  eight,  and  subtract  from  it  half  the  roots,  namely, 
five ;  the  remainder  is  three.  It  is  the  root  of  the  square  which  you  re- 
quired ;  and  the  square  is  nine. 

'  In  like  manner,  if  two  squares  be  specified,  or  three,  or  less,  or  more,  re- 
duce them  to  a  single  square  ;  and  reduce  the  roots  and  number  therewith  to 
the  like  of  that  to  which  you  reduced  the  square. 

'  For  example,  you  say  "  two  squares  and  ten  roots  are  equal  to  forty- 
eight  dirhems :"  and  the  meaning  is,  any  two  [such]  squares,  when  they  are 
summed  and  unto  them  is  added  the  equivalent  of  ten  times  the  root  of  one 
of  them,  amount  to  the  total  of  forty-eight  dirhevis.  Then  you  must  reduce 
the  two  squares  to  a  single  square:  and  assuredly  you  know,  that  one  of  two 
squares  is  a  moiety  of  both.  Then  reduce  the  whole  thing  in  the  instance  to 
its  half:  and  it  is  as  much  as  to  say,  a  square  and  five  roots  are  equal  to 
twenty-four  dirhems ;  and  the  meaning  is,  any  [such]  square,  when  five  of 
its  roots  are  added  to  it,  amounts  to  twenty-four.  Then  halve  the  roots,  and 
the  moiety  is  two  and  a  half.  Multiply  that  by  its  like,  and  the  product  is 
six  and  a  quarter.  Add  this  to  twenty-four,  the  sum  is  thirty  dirhems  and  a 
quarter.  Extract  the  root,  it  is  five  and  a  half.  Subtract  from  this  the 
moiety  of  the  roots;  that  is,  two  and  a  half:  the  remainder  is  three.  It  is 
the  root  of  the  square:  and  the  square  is  nine. 


ALGEBRA  AMONG  THE  ARABIANS.  ixxvii 

*  In  like  manner,  if  it  be  said  "  half  of  the  square  and  five  roots  are  equal 
to  twenty-eight  dirhems."  It  signifies,  that,  when  you  add  to  the  moiety  of 
any  [such]  square  the  equivalent  of  five  of  its  roots,  the  amount  is  twenty- 
eight  dirham.  Then  you  desire  to  complete  your  square  so  as  it  shall 
amount  to  one  whole  square ;  that  is,  to  double  it.  Therefore  double  it, 
and  double  what  you  have  with  it;  as  well  as  what  is  equal  thereunto! 
Then  a  square  and  ten  roots  are  equal  to  fifty-six  dirhems.  Add  half  the 
roots  multiplied  by  itself,  twenty-five,  to  fifty-six ;  and  the  sum  is  eighty-one 
Extract  the  root  of  this,  it  is  nine.  Subtract  from  this  the  moiety  of  the 
roots ;  that  is,  five  :  the  remainder  is  four.  It  is  the  root  of  the  square  which 
you  required:  and  the  square  is  sixteen;  and  its  moiety  is  eight. 

'  Proceed  in  like  manner  with  all  that  comes  of  squares  and  roots  •  and 
what  number  equals  them.  ' 

'  As  for  squares  and  number,  which  are  equal  to  roots  ;  for  example,  you 
say.  a  square  and  twenty-one  are  equal  to  ten  of  its  roots  :"  the  meaning  of 
which  IS,  any  [such]  square,  when  twenty-one  dirhems  are  added  to  it 
amounts  to  what  is  the  equivalent  of  ten  roots  of  that  square:  then  the  solu- 
tion IS,  halve  the  roots;  and  the  moiety  is  five.  Multiply  this  by  itself  the 
product  IS  twenty-five.  Then  subtract  from  it  twenty-one,  the  number'spe- 
cified  with  the  square:  the  remainder  is  four.  Extract  its  root;  which  is 
two.  Subtract  this  from  the  moiety  of  the  roots;  that  is,  from  five-  the  re- 
mainder IS  three.  It  is  the  root  of  the  square  which  you  required :' and  the 
square  ,s  nine.  Or,  if  you  please,  you  may  add  the  root  to  the  moiety  of  the 
roots,  the  sum  is  seven.  It  is  the  root  of  the  square  which  you  required- 
and  the  square  is  forty-nine.  ' 

'  When  a  case  occurs  to  you,  which  you  bring  under  this  head  try  its 
answer  by  the  sum:  and,  if  that  do  not  serve,  it  certainly  will  by  the  dif- 
ference. This  head  is  wrought  both  by  the  sum  and  by  the  difference  Not 
so  either  of  the  others  of  three  cases  requiring  for  their  solution  that  the  root 
be  ha  ved  And  know,  that,  under  this  head,  when  the  roots  have  been 
halved,  and  the  moiety  has  been  multiplied  by  its  like,  if  the  amount  of  the 
prcKluct  be  less  than  the  dirhems  which  are  with  the  square,  then  the  instance 
IS  impossible:  and,  if  it  be  equal  to  the  dirhems  between  them,  tlie  root  of 
the  square  is  like  tiie  moiety  of  the  roots,  without  either  addition  or  sub- 
traction. 

'  In  every  instance  where  you  have  two  squares,  or  more  or  less,  reduce  to 
a  Single  square,  as  I  explained  under  the  first  head. 


Ixxviii  NOTES  AND  ILLUSTRATIONS. 

'  As  for  roots  anti  number,  which  are  equal  to  squares:  for  example,  you 
say,  "  three  roots  and  four  in  number  are  equal  to  a  square:"  tlie  solution  of 
it  is,  halve  the  roots;  and  the  moiety  will  be  one  and  a  half  Multiply  this 
by  its  like,  [the  product  is  two  and  a  quarter.  Add  it  to  four,  the  sum  is  six 
and  a  quarter.  Extract  the  root,  which  is  two  and  a  half  To  this  add  the 
moiety  of  the  roots.  The  sum  is  four.  It  is  the  root  of  the  square  which 
you  required:  and  the  square  is  sixteen.]' 

The  author  retunis  to  the  subject  in  a  distinct  chapter,  which  is  entitled 
"  On  the  six  cases  of  Algebra."     A  short  extract  from  it  may  suffice. 

'The  first  of  the  six  cases.  For  example,  you  say,  "  you  divide  ten  into 
two  parts,  and  multiply  one  of  the  two  parts  by  the  other:  then  you  multiply 
one  of  them  by  itself,  and  the  product  of  this  multiplication  into  itself  is 
equal  to  four  times  that  of  one  of  the  parts  by  the  other." 

'  Solution.  Make  one  of  the  two  parts  thing,  and  the  other  ten  less  thing: 
then  multiply  thing  by  ten  less  thing,  and  the  product  will  be  ten  things  less 
a  square.  Multiply  by  four:  for  you  said  "four  times."  It  will  be  four 
times  the  product  of  one  part  by  the  other ;  that  is,  forty  things  less  four 
squares.  Now  multiply  thing  by  thing,  which  is  one  of  the  parts  by  itself: 
the  result  is,  square  e(iual  to  forty  things  less  four  squares.  Then  restore  it 
in  the  four  squares,  and  add  it  to  the  one  square.  There  will  be  forty  things 
equal  to  five  squares ;  and  a  single  square  is  equal  to  eight  roots.  It  is 
sixty-four  ;  and  its  root  is  eight :  and  that  is  one  of  the  two  parts,  which  was 
multipled  into  itself:  and  the  remainder  often  is  two;  and  that  is  the  other 
part.  Thus  has  this  instance  been  solved  under  one  of  the  six  heads  :  and 
that  is  the  case  of  squares  equal  to  roots. 

'  The  second  case.  "  You  divide  ten  into  two  parts,  and  multiply  the 
amount  of  a  part  into  itself  Then  multiply  ten  into  itself;  and  the  product 
of  this  multiplication  often  into  itself,  is  equivalent  to  twice  the  product  of 
the  part  taken  into  itself,  and  seven  ninths:  or  it  is  equivalent  to  six  times 
and  a  quarter  tlie  product  of  the  other  part  taken  into  itself. 

'  Solution.  Make  one  of  the  parts  thing,  and  the  other  ten  less  thifig. 
Then  you  multiply  thing  into  itself:  it  is  a  square.  Next  by  two  and  seven 
ninths:  the  product  will  be  two  squares,  and  seven  ninths  of  a  square.  Then 
multiply  ten  into  itself,  and  the  product  is  a  hundred.  Reduce  it  to  a  single 
square,  the  result  is  nine  twenty-fiths;  that  is,  a  fifth  and  four  fifths  of  a  fifth. 
Take  a  fifth  of  a  hundred  and  four  fifths  of  a  fifth,  the  quotient  is  thirty-six, 


I 


ALGEBRA  AMONG  THE  ARABIANS.  Ixxix 

which  is  equal  to  one  square.  Then  extract  tne  root,  which  is  six.  It  is  one 
of  the  two  parts;  and  the  other  is  undoubtedly  four.  Thus  you  solve  this 
instance  under  one  of  the  six  heads :  and  that  is  "  squares  equal  to  number." 

These  extracts  may  serve  to  convey  an  adequate  notion  of  the  manner,  in 
which  the  Khuwdrezmi  conducts  the  resolution  of  equations  simple  and 
compound,  and  the  investigation  of  problems  by  their  means.  If  a  compari- 
son be  made  with  the  Khulasetu'l  hisdb,  of  which  a  summary  by  Mr. 
Strachey  will  be  found  in  the  researches  of  the  Asiatic  society,"  it  may  be 
seen,  that  the  Algebraic  ait  has  been  nearly  stationary  in  the  hands  of  the 
Muhammedans,  from  the  days  of  Muhammed  of  Khwwdrtzm^  to  those  of 
Beha'u'ldi'.v  of  Aamul,^  notwithstanding  the  intermediate  study  of  the 
arithmetics  of  Diophantus,  translated  and  expounded  by  Muhajimed  of 
Buzjdn.  Neither  that  comparison,  nor  the  exclusive  consideration  of  the 
Khuwdrezmi  s  performance,  leads  to  any  other  conclusion,  than,  as  before  in- 
timated, that,  being  conversant  with  the  sciences  of  the  Hindus,  especially 
with  their  astronomy  and  their  method  of  numerical  calculation,  and  being 
the  author  of  the  earliest  Arabic  treatise  on  Algebra,  he  must  be  deemed  to 
have  learnt  from  the  Hindus  the  resolution  of  simple  and  quadratic  equations, 
or,  in  short,  Algebra,  a  branch  of  their  art  of  computation. 

The  conclusion,  at  which  we  have  arrived,  may  be  strengthened  by  the 
coincident  opinion  of  Cossali,  who,  after  diligent  research  and  ample  disqui- 
sition, comes  to  the  following  result.* 

'  Concerning  the  origin  of  Algebra  among  the  Arabs,  what  is  certain  is, 
that  Muhammed  ben  Musa  the  Khuwdrezmite  first  taught  it  to  them.  The 
Casb'inian,  a  writer  of  authority  affirms  it;  no  historical  fact,  no  opinion,  no 
reasoning,  opposes  it. 

'  There  is  nothing  in  history  respecting  Muhammed  hen  Musa  indi- 
vidually, which  favours  the  opinion,  that  he  took  from  the  Greeks,  the  Alge- 
bra, which  he  taught  to  the  Muhammedans. 

*  History  presents  in  him  no  other  than  a  mathematician  of  a  country  most 
distant  from  Greece  and  contiguous  to  India;  skilled  in  the  Indian  tongue; 
fond  of  Indian  matters:  which  he  translated,  amended,  epitomised,  adorned: 
and  he  it  was,  who  was  the  first  instructor  of  the  Muhammedans  in  the  Alge- 
braic art.' 

•  Vol.  12.        *  On  the  Oxus.         '  A  district  of  Syria;  not  Amal  a  town  in K/iur/tsiJii.     Com. 

♦  Orig.  deWAtg.  i.  2l6.  »  Orig.  ddl'Alg.  i.  219. 


•V 


Ixxx  NOTES  AND  ILLUSTRATIONS. 

'  Not  havin<>^  taken  Algebra  from  the  Greeks,  he  must  have  either  invented 
it  himself,  or  taken  it  from  the  ImUans.  Of  the  two,  the  second  appears  to 
me  the  most  probable.'^ 


o. 

COMMUNICATION  OF  THE  HINDUS  WTFH  WESTERN 
NATIONS  ON  ASTROLOGY  AND  AGRONOMY. 

The  position,  that  Astrology  is  partly  of  foreign  growth  in  India;  that  is, 
that  the  Hindus  have  borrowed,  and  largely  too,  from  the  astrology  of  a 
more  western  region,  is  grounded,  as  the  similar  inference  concerning  a  dif- 
ferent branch  of  divination,"  on  the  resemblance  of  certain  terms  employed 
in  both.  The  mode  of  divination,  called  Tdjaca,  implies  by  its  very  name 
its  Arabian  origin.  Astrological  prediction  by  configuration  of  planets,  in 
like  manner,  indicates  even  by  its  Indian  name  a  Grecian  source.  It  is 
denominated  Hord,  the  second  of  three  branches  which  compose  a  complete 
course  of  astronomy  and  astrology :'  and  the  word  occurs  in  this  sense  in  the 
writings  of  early  Hindu  astrologers.  Vara'ha-mihika,  whose  name  stands 
high  in  this  class  of  writers,  has  attempted  to  supply  a  Sanscrit  etymology; 
and  in  his  treatise  on  casting  nativities  derives  the  word  from  Ahordtra, 
day  and  night,  a  nycthemeron.  This  formation  of  a  word  by  dropping  both 
the  first  and  last  syllables,  is  not  conformable  to  the  analogies  of  Sanscrit  ety- 
mology. It  is  more  natural  then  to  look  for  the  origin  of  the  term  in  a 
foreign  tongue:  and  that  is  presented  by  the  Greek  <J'fa  and  its  derivative 
wf  oo-xoTT^,  an  astrologer,  and  especially  one  who  considers  the  natal  hour,  and 
hence  predicts  events.*  The  same  term  hard  occurs  again  in  the  writings  of 
the  Hindu  astrologers,  with  an  acceptation  (that  of  hour')  which  more 
exactly  conforms  to  the  Grecian  etymon. 

The  resemblance  of  a  single  term  would  not  suffice  to  giound  an  inference 
of  common  origin,  since  it  might  be  purely  accidental.  But  other  words  are 
also  remarked  in  Hindu  astrology,  which  are  evidently  not  Indian.     An  in- 

•  See  his  reasons  at  large.  *  As.  Res.  9.  3/6.  '  Sec  Note  K. 

♦  Hes^ch.  and  Suid.  »  .\s.  Res.  5.  XOJ. 


COMMUNICATION  ON  ASTROLOGY,  &c.  Ixxxi 

stance  of  it  is  dreshcdna,^  used  in  the  same  astrological  sense  with  the  Greek 
SixMi^  and  Latin  decanus :  words,  which,  notwithstanding  their  classic  sound, 
are  to  be  considered  as  of  foreign  origin  (Chaldean  or  Egyptian)  in  the  classic 
languages,  at  least  with  this  acceptation.^  The  term  is  assuredly  not  genuine 
Sanscrit;  and  hence  it  was  before*  inferred,  that  the  particular  astrological 
doctrine,  to  which  it  belongs,  is  exotic  in  India.  It  appears,  however,  that 
this  division  of  the  twelve  zodiacal  signs  into  three  portions  each,  with 
planets  governing  tliem,  and  pourtrayed  figures  representing  tlieni,  is  not  im- 
plicitly the  same  among  the  Hindu  astrologers,  which  it  was  among  the  Chal- 
deans, with  whom  the  £g3'ptians  and  Persians  coincided.  Variations  have 
been  noticed.'  Other  points  of  difference  are  specified  by  the  astrologer  of 
Ballch*  and  they  concern  the  allotment  of  planets  to  govern  the  decani  and 
dreshcdnas,  and  the  figures  by  which  they  are  represented.  Abu-mashar  is  a 
writer  of  the  ninth  century;*  and  his  notice  of  this  astrological  division  of 
the  zodiac  as  received  by  Hindus,  Chaldeans,  and  Egyptians,  confirms  the 
fact  of  an  earlier  communication  between  the  Indians  and  the  Chaldeans,  per- 
haps the  Egyptians,  on  the  subject  of  it. 

With  the  sexagesimal  fractions,  the  introduction  of  which  is  by  Wallis 
ascribed  to  Ptolomy  among  the  the  Greeks,'  the  Hindus  have  adopted  for 
the  minute  of  a  degree,  besides  a  term  of  their  own  language,  cala,  one  taken 
from  the  Greek  Xt-rrlx  scarcely  altered  in  the  Sanscrit  Uptd.  The  term  must 
be  deemed  originally  Greek,  rather  than  Indian,  in  that  acceptation,  as  it 
there  corresponds  to  an  adjective  Xnr]^,  slender,  minute:  an  import  which 
precisely  agrees  wth  the  Sanscrit  cald  and  Arabic  dak'tk,  fine,  minute;  whence, 
in  these  languages  respectively,  cald  and  dak'ik  for  a  minute  of  a  degree. 
But  the  meanings  of  Uptd  in  Sanscrit^  are,  1st,  smeared;  2d,  infected  with 
poison;  3d,  eaten:  and  its  derivative /i/>/f«ca  signifies  a  poisoned  arrow,  being 
derived  from  Up,  to  smear:  and  the  dictionaries  give  no  interpretation  of  the 
word  that  has  any  affinity  with  its  special  acceptation  as  a  technical  term  in 
astronomy  and  mathematics.  Yet  it  occurs  so  employed  in  the  work  of 
Brahmegupta.' 

By  a  different  analogy  of  the  sense  and  not  the  sound,  the  Greek  in-oX^a,  a 

•  As.  Res.  9.  36'7.  »  Ibid.     Vide  Sulm.  Exerc.  Plin.  ^  Jbid.  9-  374. 

*  Lib.  intr.  in  Ast.  Albumasis  Abalachi,  5.  12  and  13. 
'  Died  in  272  H.  (885  C.)  aged  a  hundred. 

«  Wallis.  Alg.  c.  7.  ^  Am.  Coth.  »  C.  1.  §  6,  et  passim. 

m 


Ixxxii  .0/    NOTES  AND  ILLUSTRATIONS. 

part,  and' specially  addgree  of  a  circle,^is  in  Sanscrit  anio,  bh/iga,  and  other 
synonyma  of  part,  applied  emphatically  in  technical  language  to  the  360th 
part  of  the  periphery  of  a  circle.  The  resemblance  of  the  radical  sense,  in 
the  one  instance,  tends  to  corroborate  the  inference  from  the  similarity  of 
sound  in  the  other.  fi 

Cendra  is  used  by  Brahmegupta  and  the  Surya-sidd' hanta,  as  well  as 
other  astronomical  writers  (Bha'scaua,  &c.),  and  by  the  astrologers  Vaua'ha- 
MiHiRA  and  the  rest,  to  signify  the  equation  of  the  centre.'  The  same  term 
is  employed  in  the  Indian  mensuration  for  the  centre  of  a  circle  ;*  also 
denoted  by  medliya,  middle.  It  comes  so  near  in  sound,  as  in  signification, 
to  the  Greek  xfWfop,  tliat  the  inference  of  a  common  origin  for  these  words 
is  not  to  be  avoided.  But  in  Sanscrit  it  is  exclusively  technical ;  it  is 
unnoticed  by  the  vocabularies  of  the  language;  and  it  is  not  easily  traced 
to  a  Sanscrit  root.  In  Greek,  on  the  contrary,  the  correspondent  term  was 
borrowed  in  mathematics  from  a  familiar  word  signifying  a  goad,  spur,  thorn, 
or  point ;  and  derived  from  a  Greek  theme  xti1««. 

The  other  term,  which  has  been  mentioned  as  commonly  used  for  the 
centre  of  a  circle,  namely  med'hya,  middle,  is  one  of  the  numerous  instances 
of  radical  and  primary  analogy  between  the  Sanscrit  and  the  Latin  and 
Greek  languages.  It  is  a  common  word  of  the  ancient  Indian  tongue ;  and 
is  clearly  tlie  same  with  the  Latin  medius;  and  serves  to  show  that  the 
Latin  is  nearer  to  tlie  ancient  pronunciation  of  Greek,  than  /aeV^  ;  from 
which  SiPONTiNus  derives  it;  but  which  must  be  deemed  a  coirupted  or 
softened  utterance  of  an  ancient  term  coming  nearer  to  the  Sanscrit  med'hyas 
and  Latin  medius.  -a 

On  a  hasty  glance  over  the  JAtacas  or  Indian  treatises  upon  horoscopes, 
several  other  terms  of  the  art  have  been  noticed,  which  are  not  Sanscrtt,  but 
apparently  barbarian.  For  instance  anapha,  suiiapha,  dui'iidhara,  and 
ceviadrnma,  designating  certain  configurations  of  tlie  planets.  They  occur 
in  both  the  treatises  of  Vaka'ua-mihira  ;  and  a  passage,  relative  to  this  sub- 
ject, is  among  those  quoted  from  the  abridgment  by  the  scholiast  of  the 
greater  treatise,  and  verified  in  the  text  of  the  less.*    The  affinity  of  those 

•  Brahm.  sidcT/i.  c.  2.  Sur.  Sidd'/i.  c.  2.  Vr'ihat  and  Laghu  Mtacas.  '  Sur.  on  L'll.  §  207- 

'  See  p.  xlix.  Another  passage  so  quoted  and  verified  uses  the  terra  cendra  in  the  sense  above- 
mentioned. 


COMMUNICATION  ON  ASTROLOGY,  &c.  Ixxxiii 

terms  to  words  of  other  languages  used  in  a  similar  astrological  sense,  has  not 
been  traced:  for  want,  perhaps,  of  competent  acquaintance  with  tlie  tiermi- 
nology  of  that  ; silly  art.  But  it  must  not  be  passed  unremarked,  that 
Varaha-mihira,  who  hag  ui  another  place  praised  the  Yavanas  for  their 
proficiency  in  astrology  (or  astronomy ;  for  the  term  is  ambigiious ;)  fre- 
quently quotes  them  in  his  great  treatise  on  horoscopes:  and  his  scholiast 
marks  a  distinction  between  the  ancient  Yavanas,  whom  he  characterises  as 
"  a  race  of  barbarians  conversant  with  (Iwrd)  horoscopes,"  and  a  known 
Sanscrit  author  bearing  the  title,  of  Yavaniis'wara,  whose  work  he  had  seen 
and  repeatedly  cites  ;  but  the  writings  and  doctrine  of  the  ancient  Yavanas, 
he  acknowledges,  had  not  been  seen  by  him,  ^nd  were  known  to  him  only  by 
this  writer's  and  his  own  author's  references. 

No  argument,  bearing  upon  the  point  under  consderation,  is  built  on 
Bha'scara's  use  of  the  word  dramina  for  the  value  of  64  cowry-shells  {Ltl. 
§2.)  in  place  of  the  proper  Sanscrit  term  />7'tf;//««a, .  which  Suid'hara  and 
other  Hindu  authors  employ ;  nor  on  the  use  of  dindra,  for  a  denomination 
of  money,  by  the  scholiast  of  Brahmegupta  (12  §  12.)  who  also,  like 
Bha'scara,  employs  the  first  mentioned  word  (12.  §  14.):  though  tl-e  one  is 
clearly  analogous  to  the  Greek  drachma,  a  word  of  undoubted  Grecian  ety- 
mology, being  derived  from  ^f  alrojuai ;  and  the  other  apparently  is  so,  to  the 
Roman  denarius  which  has  a  Latin  derivation.  The  first  has  not  even  the 
Sanscrit  air ;  and  is  evidently  an  exotic,  or,  in  short,  a  barbarous  term.  It 
was  probably  received  mediately  through  the  Muhammedans,  who  have 
their  dirhem  in  the  like  sense.  The  other  is  a  genuine  Sanscrit  word,  of 
which  the  etymology,  presenting  the  sense  of  '  splendid,'  is  consistent  with 
the  several  acceptations  of  a  specific  weight  of  gold  ;  a  golden  ornament  or 
breast-piece;  and  gold  money  :  all  which  senses  it  bears,  according  to  the 
ancient  vocabularies  of  the  lansruasre.* 

The  similarity  seems  then  to  be  accidental  in  this  instance ;  and  the  Mu- 
hammedans, who  have  also  a  like  term,  may  have  borrowed  it  on  either 
hand:  not  improbably  from  the  Hindus,  as  the  dinar  of  the  Arabs  and  Per- 
sians is  a  gold  coin  like  the  Indian  ;  while  the  Roman  denarius  is  properly  a 
silver  one.  D'Herbelot  assigns  as  a  reason  for  deriving  the  Arabic  dindr 
from  the  Roman  denarius,  that  this  was  of  gold.     The  nummus  aureus  some- 

'  Amera-cosha,  Sec. 

m2 


Ixxxiv  NOTES  AND  ILLUSTRATIONS. 

times  had  that  designation ;  and  we  read  in  Roman  authors  of  golden  as  well 
as  silver  denarii.^  But  it  is  needless  to  multiply  references  and  quotations 
to  prove,  that  the  Roman  coin  of  that  name  was  primarily  silver,  and  so 
denominated  because  it  was  equal  in  value  to  ten  copper  a*;*  tliat  it  was  all 
along  the  name  of  a  silver  coin;'  and  was  still  so  under  the  Greek  empire, 
when  the  irty»gK>ti  was  the  hundredth  part  of  a  large  silver  coin  termed 

dfyupa!* 

»  Plin.  33.  §  13,  and  37  §  3.  Petron.  Satyr.  106.  l60. 
•  rim.  33.  13  VUr.  3.  1.  Voliu.  Mxcimus.  Didyraus. 
'  Vitr.  and  Vol.  Maec.  *  Epiphanius,  cum  raultis  aliis. 


INDIAN 

aritljmetic  anti  Algebra* 

CHAPTER  I. 

INTRODUCTION. 

1.  Having  bowed  to  the  deity,  whose  head  is  Hke  an  elephant's;' 
whose  feet  are  adored  by  gods ;  who,  when  called  to  mind,  relieves  his  vota- 
ries from  embarrassment ;  and  bestows  happiness  on  his  Avorshippers ;  I 
propound  this  easy  process  of  computation,'  delightful  by  its  elegance,* 
perspicuous  with  words  concise,  soft  and  correct,  and  pleasing  to  the  learned. 

AXIOMS. 

[consisting  in  definitions  gf  technical  terms.] 

[Money  by  Tale.] 

2.  Twice  ten  cowry  shells*  are  a  c^cini ;  four  of  these  are  apana;  sixteen 
of  which  must  be  here  considered  as  a  dramma  ;  and  in  like  manner,  a  nishca, 
as  consisting  of  sixteen  of  these. 


Gan'es'a,  represented  with  an  elephant's  head  and  human  body. 
Pdt'i-ganita ;  ji&t'i,  paripdti,  or  vyacia-ganj^rt,  arithmetic. 

*  Lildvati  delightful :  an  allusion  to  the  title  of  the  book.     See  notes  on  §  13  and  277. 

♦  Cypiaea  moneta.     Sans.  Vara'taca,  capardi ;  Hind.  Cauri. 

B 


2  LI'LAVATI'.  .  .    Chapter  I. 

[FFdglKs.] 

3.  A  gunja^  (or  seed  of  Abrus)  is  reckoned  ccjual  to  two  barley-corns  ;  a 
•calla,  to  two  gunjas;  and  eight  of  tiiose  are  »  iJmrana ;  two  of  which 
make  a  gadydtiaca.  In  like  manner  one  dha'taca  is  composed  of  fourteen 
vallas.  ' 

4.  Half  ten  gunjas  are  called  a  mAsha,''  by  such  as  are  conversant  with 
the  use  of  the  balance :  a  carsha  contains  sixteen  of  what  are  termed  mdshas; 
a  pala,  four  carshas.     A  carsha  of  gold  is  named  suverna. 

[Measures.} 

5 — 6.  Eight  breadths  of  a  barley-coni'  are  here  a  finger ;  four  times  six 
fingers,  a  cubit  ;*  four  cubits,  a  staflF;'  and  a  crosa  contains  two  thousand  of 
these  ;  and  a  ydjana,  four  crosas. 

So  a  banibu  pole  consists  of  ten  cubits ;  and  a  field  (or  plane  figure) 
bounded  by  four  sides,  measuring  twenty  bambu  poles,  is  a  nivartana." 

7,  A  cube,''  which  in  length,  breadth  and  thickness  measures  a  -cubit,  is 
termed  a  solid  cubit :  and,  in  the  meting  of  com  and  the  like,  a  measure. 


•  A  seed  of  Abrus  precatorius :  black  or  red ;  the  one  called  crishtiala  ;  the  other  racti,  racticd 
or  ratticd;  whence  Hind,  ratti. 

'  Physicians  reckon  seven  gunjas  to  the  m&slia;  lawyers,  seven  and  a  half.  The  same  weight  is 
intended ;  and  the  difference  of  description  arises  only  from  counting  by  heavier  or  lighter  seeds 
of  Abrus  :  in  like  manner  as  the  earth  is  the  same,  whether  rated  at  3300  ydjanas  ;  or,  with  the 
Siromani,  4967  ;  or,  according  to  others,  6522.  Gan. 

^  Eight  barley-corns  (yma)  by  breadth,  or  three  grains  of  rice  by  length,  a,K  equal  to  one  finger 
(angttla).  Gan'. 

*  Haifa,  cara  and  synonyma  of  hand  or  fore  arm.  According  to  the  commentator  Gan'e's'a,  this 
intends  the  practical  cubit  as  received  by  artisans,  and  vulgarly  called  gaj  [or  gaz].  It  is  nearer 
to  the  yard  than  to  the  true  cubit :  but  the  commentator  seems  to  have  no  sufficient  ground  for 
so  enlarging  the  cubit. 

5  Dan'da,  a  staff:  directed  to  be  cut  nearly  of  man's  height.  'Mb»u,  S.  46, 

"  A  superficial  measure  or  area  containing  400  square  poles.  Sur. 

'  Du&dai&sri,  lit.  dodecagon,  but  meaning  a  parallelopipedon  ;  the  term  asra,  corner  or  angle, 

being  here  applied  to  the  edge  or  line  of  incidence  of  two  planes.     See  Cuaturve'da  on  Brah- 

MEOUPTA,  §6. 


WEIGHTS  AND  MEASURES.  3 

which  contains  a  solid  cubit,  is  a  c'hari  of  Magad'ha '  as  it  is  denominated 
in  science. 

8.  A  drofia  is  the  sixteenth  part  of  a  chart;  an  ad'haca  is  a  quarter  of  a 
drbna ;  a.  pros f  ha  is  a  fourth  part  of  an  ad'haca ;  and  a  cudaba''  is  by  the 
ancients'  termed  a  quarter  of  a  prasfha* 

The  rest  of  the  axioms,  relative  to  tiine*  and  so  forth,  are  familiarly 
known.* 


'  The  country  or  province  situated  on  the  Sonebhadra  river. — Gan.  It  is  South  Bihar.  See, 
concerning  other  c'hdri  measures,  a  note  on  §  236. 

*  '  In  the  Cutapa,  the  depth  is  a  finger  and  a  half;  the  length  and  breadth,  each,  three.' 
Seid'hara  a'cha'rta  cited  by  Ganga'd'hara  and  Su'ryada'sa.  '  The  cutapa  or  ctidaba  is  a 
wooden  measure  containing  13  J  c\ih\c  angulas  ;  thepr<ut'/ia,  (four  times  as  many)  54;  the  ffd'haca, 
2]  6;  the  droiia,  864;  the  c'h&ri,  13824.'— Gang,  and  Su'r.     See  As.  Res.  vol.  5,  p.  102. 

*  By  Sri'd'hara  and  the  rest.  Sun. 

■*  Another  stanza,  (an  eighth,  on  the  subject  of  weights  and  measures,)  occurs  in  one  copy  of 
the  text;  and  that  number  is  indicated  in  the  Manoranjana.  But  the  commentaries  of  Ganesa 
and  Su'ryada'sa  specify  seven,  and  Ganga'd'hara  alone  expounds  the  additional  stanza.  It  is 
therefore  to  be  rejected  as  spurious,  and  interpolated  :  not  being  found  in  other  copies  of  the  text. 
The  subject  of  it  is  the  mana  (mati)  of  forty  setas  (ser)  ;  which,  as  a  measure  of  com  by  weight, 
is  ascribed  to  the  Turushcas  or  Muhammedans  of  India ;  the  people  of  Yacana-desa,  as  the  com- 
mentator terms  them. 

"  The  seta*  is  here  reckoned  at  twice  seven  tancas,  each  equal  to  three-fourths  oia.  gadydnaca: 
and  a  mana,  at  forty  setas.  The  name  is  in  use  among  the  Turushcas,  for  a  weight  of  com  and  like 
articles."     See  notes  on  §  97  and  236. 

'  The  author  has  himself  explained  the  measures  of  time  in  the  astronomical  part  of  his  treatise. 
(Sidd'h&nta-siromam,  S  l6-l  8.J  Gang,  and  Su'r. 

•  Concerning  weights  and  measures,  see  GamVa-^ifra  of  Srid'hara,  §4 — 8;  and  PRfxauDACA 
sitamiChAturv^da  on  Brahmegupta's  arithmetic,  §  lO-U. 

•  The  copy  of  Ganoa'd'hara's  commentary  writes  saura.  But  the  exemplar  of  the  text,  con- 
taining the  passage,  has  seta. 


B  2 


y 


CHAPTER   11. 


SECTION  I. 


Invocation.'^ 


9-  Salutation  to  G  an'es'a,  resplendent  as  a  blue  and  spotless  lotus;  and 
delighting  in  the  tremulous  motion  of  the  dark  serpent,  which  is  perpetually- 
twining  within  his  throat. 

Numeration. 
10 — 11.  Names  of  the  places  of  figures  have  been  assigned  for  practical 
use  by  ancient  writers,*  increasing  regularly'  in  decuple  proportion  :  namely, 
unit,  ten,  hundred,  thousand,  myriad,  hundred  thousands,  million,  ten 
millions,  hundred  millions,  thousand  millions,  ten  thousand  millions,  hundred 
thousand  millions,  billion,  ten  billions,  hundred  billions,  thousand  billions, 
ten  thousand  billions,  hundred  thousand  billions.* 


'  A  reason  of  this  second  introductory  stanza  is,  that  the  foregoing  definitions  of  terms  are  not 
properly  a  part  of  the  treatise  itself;  nonesuch  having  been  premised  by  Arya-biiatt'a  and  other 
ancient  authors  to  their  treatises  of  arithmetic.  Gan.  and  Mono. 

^  According  to  the  Hindus,  numeration  is  of  divine  origin  ;  '  the  invention  cf  nine  figures  (anca), 
with  the  device  of  places  to  make  them  suffice  for  all  numbers,  being  ascribed  to  the  beneficent 
Creator  of  the  universe,'  in  Bhascara's  Vdsand  and  its  gloss;  and  in  Crishna's  commentary  on 
the  Vija-garika.  Here  nine  figures  are  specified ;  the  place,  when  none  belongs  to  it,  being  shown 
by  a  blank  (sunya)  ;  which,  to  obviate  mistake,  is  denoted  by  a  dot  or  small  circle. 

'  From  the  right,  where  the  first  and  lowest  number  is  placed,  towards  the  left  hand.    Gas.  &c. 

♦  Sans,  ka,  daia,  sata,  sahasra,  ayuta,  lacsha,  prayuta,  coti,  arbuda,  abja  or  padma,  c'/iarva, 
nic'harva,  mahdpadma,  sancu,jalad'hi  or  samudra,  antya,  mad'hya,  par&rd'ha. 

A  passage  of  the  Veda,  which  is  cited  by  Su'rya-dasa,  contains  the  places  of  figures.  'Be 
these  the  milch  kine  before  me,  one,  ten,  a  hundred,  a  thousand,  ten  thousand,  a  hundred  thousand, 
a  million Be  these  milch  kine  my  guides  in  this  world.' 

Ga'n'esa  observes,  that  numeration  has  been  carried  to  a  greater  number  of  places  by  Srid'iiara 
and  others ;  but  adds,  that  the  names  are  omitted  on  account  of  the  numerous  contradictions  and 
the  little  utility  of  tljose  designations.  The  text  of  the  Gaiiita-s/ira  or  abridgment  of  Srid'hara 
does  not  correspond  with  this  reference :  for  it  exhibits  the  same  eighteen  places,  and  no  more. 
Gari-sdr.  §  2—3.) 


(     5     ) 


SECTION  II. 

Eight  Operations'  of  Arithmetic. 

12.  Rule  of  addition  and  subtraction  :*  half  a  stanza. 

ITie  sum  of  the  figures  according  to  their  places  is  to  be  taken  in  the 
direct  or  inverse  order  :'  or  [in  the  case  of  subtraction]  their  difference. 

13.  Example.  Dear  intelligent  Lila'vati,*  if  thou  be  skilled  in  addition 
and  subtraction,  tell  me  the  sum  of  two,  five,  thirty-two,  a  hundred  and 
ninety-three,  eighteen,  ten,  and  a  hundred,  added  together;  and  the  re- 
mainder, when  their  sum  is  subtracted  from  ten  thousand. 

Statement,  2,  5,  32,  193,  18,  10,  100. 
[Answer.]     Result  of  the  addition,  360. 
Statement  for  subtraction,  10000,  360. 
[Answer.]     Result  of  the  subtraction,  9640. ' 


14 — 15.     Rule  of  multiplication:*  two  and  a  half  stanzas. 

Multiply  the  lasf  figure  of  the  multiplicand  by  the  multiplicator,  and 

'  ParJcamniiA/aca,  eight  operations,  or  modes  of  process  :  logistics  or  algorism. 

*  Sancalana,  sancalita,  misrana,  yuti,  yoga,  &c.  summation,  addition.     Vyavacalana,  ryacacalita, 
sod'hana,  patana,  &c.  subtraction.     Antara,  difference,  remainder. 

'  From  the  first  on  the  right,  towards  the  left;  or  from  the  last  on  the  left,  towards  the  right. 

Gang. 
•   *  Seemingly  the  name  of  a  female  to  whom  instruction  is  addressed.     But  the  term  is  interpreted 
in  some  of  the  commentaries,  consistently  with  its  etymology,  "  Charming." — See  ^  1.  and  'ilJ. 

*  Mode  of  working  addition  as  shown  in  the  Manoranjana  : 

Sum  of  the  units,     2,  5,  2,  3,  8,  0,  0, 20 

Sura  of  the  tens,  3,9,1,1,0, 14 

Sum  of  the  hundreds,  1,0,0,1, 2 

Sum  of  the  sums 360 

*  Gtinuna,abhydsa ;  also  hanuna  and  any  terra  implying  a  tendency  to  destroy.     It  is  denominated 
fratyutpanna  by  Brahmecvpta,  §  3  ;  and  by  Srid'haka,  §  15 — 17- 

Guhya  multiplicand.    Guiiaca  multiplicator.     Ghdia  product. 

*  The  digit  standing  last  towards  the  left.    The  work  may  begin  either  from  the  first  or  the  last 
digit,  according  to  Srid'iiara.  Gaiiila-t&ra,  §  15. 


\ 


6  LI'LAVATr.  Chapter  II. 

next  the  penult,  and  then  the  rest,  by  the  same  repeated.  Or  let  the  mul- 
tiplicand be  repeated  under  the  several  parts  of  the  multiplicator,  and  be 
multiplied  by  those  parts :  and  the  products  be  added  together.  Or  the 
multiplier  being  divided  by  any  number  which  is  an  aliquot  part  of  it,  let 
the  multiplicand  be  multiplied  by  that  number  alid  then  by  the  quotient,  the 
result  is  the  product.  These  are  two  methods  of  subdivision  by  form.  Or 
multiply  separately  by  the  places  of  figures,  and  add  the  products  together. 
Or  multiply  by  the  multiplicator  diminished  or  increased  by  a  quantity 
arbitrarily  assumed  ;  adding,  or  subtracting,  the  product  of  the  multiplicand 
taken  into  the  assumed  quantity.' 

16.  Example.  Beautiful  and  dear  Lila'vati,  whose  eyes  are  like  a 
fawn's !  tell  me  what  are  the  numbers  resulting  from  one  hundred 
and  thirty-five,  taken  into  twelve?  if  thou  be  skilled  in  multiplication 
by  whole  or  by  parts,  whether  by  subdivision   of  form  or  separation  of 


'  The  author  teaches  six  methods,  according  to  the  exposition  of  Su'eyada'sa,  &c.  ;  but  seven, 
as  interpreted  by  Ganga'd'hara  :  and  those,  combined  with  the  four  of  ScANftASEirA  and 
Srid'hara,  (one  of  which  at  the  least  is  unnoticed  by  Bha'scara,)  make  eight  distinct  ways. 
The  mode  of  multiplication  by  parts  ('c'Aa«(ia-praci{ra)  is  distinguished  into  r&pa-tibhaga  and 
sfkina-vibhAga,  or  subdivision  of  the  form  and  severance  of  the  digits  :  the  first  is  again  divided  into 
multiplication  by  integrant  or  by  aliquot  parts :  the  second  in  like  manner  furnishes  two  ways, 
according  as  the  digits  of  the  multiplier  or  of  the  multiplicand  are  severed.  These  then  are  four 
methods,  deduced  from  two  of  Scandase'na  and  Srid'hara  ;  to  which  two  others  are  added  by 
Bha'scara,  consisting  in  the  increase  or  decrease  of  the  multiplier  by  an  arbitrary  quantity,  and 
taking  the  sum  or  difference  of  the  products.  To  those  six  must  be  joined  the  Tatst'ha  of  the  older 
authors,  and  their  CapAtasattd'hi ;  if  indeed  this  be  not  (conformably  with  Gang  a'd'hara's  opinion,) 
intended  by  Biia'scara's  first  method.  It  is  wrought  by  repeating  or  moving  the  multiplier  over 
(accordihg  to  GAtrcA'D'HARA,  or  under,  as  directed  by  the  ManormijaiM,)  every  digit  of  the 
multiplicand  ;  and,  according  to  the  explanation  of  Gan'e's'a,  it  proceeds  obliquely,  joining 
products  along  compartments.  The  tatst'ha,  so  named  because  the  multiplier  is  stationary,  appears 
from  Gan'e's'a's  gtess  to  be  cross  multiplication.  '  After  setting  the  multiplier  under  the  multi- 
plicand,' he  directs  to  '  multiply  unit  by  unit,  and  note  the  result  underneath.  Then,  as  in  cross 
multiplication,*  multiply  unit  by  ten,  and  ten  by  unit,  add  together,  and  set  down  the  sum  in  a 
line  with  the  foregoing  result.  Next  multiply  unit  by  hundred,  and  hundred  by  unit,  and  ten 
by  ten  ;  add  together,  and  set  down  the  result  as  before:  and  so  on,  with  the  rest  of  the  digits. 
This  being  done,  the  line  of  results  is  the  product  of  the  multiplication.'  The  commentator 
considers  this  method  as  '  diflicult,  and  not  to  be  learnt  by  dull  scholars  without  oral  instruction.' 
He  adds,  that '  other  modes  may  be  devised  by  the  intelligent.'  See  Arithm.  of  Brahm.  §  55, 
Gan.-sh:  §  15—17. 

*  Vajr&bhy6ia.     See  V'ya-ganita,  §  77- 


S£CT.  II. 


LOGISTICS. 


digits.'     Tell  me,  auspicious  womau,  what  is  the  quotient  of  the  product 
divided  by  the  same  multiplier  } 

Statement,   Multiplicand  135.     Multiplicator  12. 

Product  (multiplying  the  digits  of  the  multiplicand  successively  by  the 

multiplicator)  2620 

Or,  subdividing  the  multiplicator  into  parts,  as  8  and  4 ;  and  severally 
multiplying  the  multiplicand  by  them ;  adding  the  products  together : 
the  result  is  the  same,  ]g20. 

Or,  the  multiplicator  12  being  divided  by  three,  the  quotient  is  4;  by 
which,  and  by  3,  successively  multiplying  the  multiplicand,  the  last 
product  is  the  same,  1620. 

Or,  taking  the  digits  as  parts,  viz.  1  and  2  ;  the  multiplicand  being  multi- 
plied by  them  severally,  and  the  products  added  together,  according  to 
the  places  of  figures,  the  result  is  the  same,  1620. 

Or,  the  multiplicand  being  multiplied  by  the  multiplicator  less  two,  viz. 

10,  and  added  to  twice  the  multiplicand,  the  result  is  the  same,  1620. 
Or,  the  multiplicand  being  multiplied  by  the  multiplicator  increased  by 
ejght,  viz.  ao,  and  eight  times  the  multiplier  being  subti:acted,  the 
result  is  the  same,  1620, 


'  The  following  scheme  of  the  process  of  multiplication  is  exhibited 
in  Gan'e's'a's  commentary. 


Or  the  process  may  be  thus  ordered,  according  to  Ganga'd'hara, 

12  12     12        Or,  in  this  manner,     135     135 

13  5  12 


12  60 

36 


1620 


Or  in  the  subjoined  modes  taken  from  Chaturveda,  &c. 
135     1      135  135     8     1080 

135     2       270  135     4       540 


1620 


1620 


270 
135 


1620 


1  /  S/  5 

1     S     2     0 


135     20     2700 
135       8     1080 

1620 


% 


«  LI'LAVATl'.  Chapter  II. 

17.     Rule  of  division.'     One  stanza. 

That  number,  by  which  the  divisor  being  multiplied  balances  the  last 
digit  of  the  dividend  [and  so  on'],  is  the  quotient  in  division  :  or,  if  practi- 
cable, first  abridge'  both  the  divisor  and  dividend  by  an  equal  number,  and 
proceed  to  division. 

[Example.]  Statement  of  the  number  produced  by  multiplication  in  the 
foregoing  example,  and  of  its  multiplicator  for  a  divisor:  Dividend  1620. 
[Divisor  12.] 

Quotient  135  ;  the  same  with  the  original  multiplicand.* 
Or  both  the  dividend  and  the  divisor,  being  reduced  to  least  terms  by  the 
common  measure  three,  are  540  and  4 ;   or  l)y  the  con)mon  measure  four, 
they  become  405  and  3.     Dividing  by  the  respective  reduced  divisors,  the 
quotient  is  the  same,  1 35. 

18 — 19-     Rule  for  the  square'  of  a  quantity:  two  stanzas. 

The  multiplication  of  two  like  numbers  together  is  the  square.  Tlie 
squareof  the  last'digit  is  to  be  placed  over  it;  and  the  rest  of  the  digits,  doubled 
and  multiplied  by  that  last,  to  be  placed  above  them  respectively;  then  repeat- 
ing the  number,  except  the  last  digit,  again  [perform  the  like  operation].  Or 
twice  the  product  of  two  parts,  added  to  the  sum  of  the  squares  of  the  parts, 
is  the  square  [of  the  whole  number].^     Or  the   product  of  the   sum  and 


'  Bh6ga-hdra,  hMjana,  hararia,  ch'hedana  :  division.  BMjya,  dividend.  Bh&jaca,  fiara,  divisor. 
LabtThi,  quotient. 

*  Repeating  the  divisor  for  every  digit,  like  the  multiplier  in  multiplication.  Gang. 
'  Apaxartiia,  abridging.     See  note  on  §  249. 

*  The  process  of  long  division  is  exhibited  in  the  Manoranjana  thus:  The  highest  places  of  the 
proposed  dividend,  l6,  being  divided  by  12,  the  quotient  is  1 ;  and  4  over.  Then  42  becomes  the 
highest  remaining  number,  which  divided  by  12  gives  the  quotient  3,  to  be  placed  in  a  line  with 
the  preceding  quotient  (1):  thus  13.  Remains  60,  which,  divided  by  12,  gives  5:  and  this  being 
carried  to  the  same  line  as  before,  the  entire  quotient  is  exhibited  :  viz.  135.  Man6r. 

'  Varga,  crtti,  a  square  number. 

*  The  process  may  begin  with  the  first  digit:  as  intimated  by  the  author,  §  24. 

'  Let  the  portions,  or  quantities  comprising  the  first  and  last  figures,  be  represented  by  the  first 
letters  of  the  alphabet,  says  the  commentator  on  the  Vhand:  Then,  proceeding  by  the  rule  of 
multiplication,  there  results  av\,  a.d g\,  a.igl,  &v\  ;  and,  adding  together  like  terms,  av\, 
a.  &g2,  (1  V  ].  Rang. 


Sect.  II.  LOGISTICS.  9 

difference  of  the  number  and  an  assumed  quantity,  added  to  the   square 
of  the  assumed  quantity,  is  the  square.' 

20.  Example.  Tell  me,  dear  woman,  the  squares  of  nine,  of  fourteen, 
of  three  hundred  less  three,  and  of  ten  thousand  and  five,  if  thou  know  the 
method  of  computing  the  square. 

Statement,  9,  14,  297,  10005. 

[Answer.]  Proceeding  as  directed,  the  squares  are  found:  81,  196, 
88209,  100,100,025. 

Or,  put  4  and  5,  parts  of  nine.  Their  product  doubled  40,  added  to  the 
sum  of  their  squares  41,  makes  81. 

So,  taking  10  and  4,  parts  of  fourteen.  Their  product  40,  being  doubled, 
is  80;  which,  added  to  116,  the  sum  of  the  squares  100  and  16,  makes  the 
entire  square,  196. 

Or,  putting  6  and  8.  Their  product  48,  doubled,  is  96 ;  which,  added  to 
the  sum  of  the  squares  36  and  64,  viz.  100,  makes  the  same,  li)6. 

Again,  297,  diminished  by  three,  is  294 ;  and,  in  another  place,  increased  by 
the  same,  is  SOO.  The  product  of  these  is  88200;  to  which  adding  the 
square  of  three  9,  the  sum  is  as  before  the  square,  88209. 

21.  Rule  for  the  square-root :  *  one  stanza. 

Having  deducted  from  the  last  of  the  odd  digits'  the  square  number, 


The  proposed  quantity  may  be  divided  into  three  parts  instead  of  two;  and  the  products  of  the 
first  and  second,  first  and  third,  and  second  and  third,  being  added  together  and  doubled,  and 
added  to  the  turn  of  the  squares  of  the  parts,  the  total  is  the  square  sought.  Gan. 

'  Another  method  is  hinted  in  the  author's  note  on  this  passage ;  consisting  in  adding  together 
the  product  of  the  proposed  quantity  by  any  assumed  one,  and  its  product  by  the  proposed  lesstha 
assumed  one.  Rang. 

*  Varga-mula  root  of  the  square  :  Mula,  pada,  and  other  synonyraa  of  root. 

'  Every  uneven  place  is  to  be  marked  by  a  vertical  line,  and  the  intermediate  even  digits  by  a 
horizontal  one.  But,  if  the  last  place  be  even,  it  is  joined  with  the  contiguous  odd  digit.  Ex. 
882oy. 

From  the  last  uneven  place  8,  deduct  the  square  4,  remains  4  8  20  9.  Double  the  root  2,  and 
divide  by  that  (4)  the  subsequent  even  digit  48  :  quotient  nine  [a  higher  one  cannot  be  taken  for 
the  root  of  the  foregoing  digit  would  become  greater  than  2  :]  the  remainder  is  12209.  From 
the  uneven  place  [with  the  residue]  12  2,  subtract  the  square  of  the  quotient  9,  viz.  81,  the  remainder 
i*  4 1 0  9-    The  double  of  the  quotient  18  is  to  be  placed  in  a  line  with  the  former  double  uuniber 

c 


VO  LI'LAVATI'.  Chapter  II. 

doul)]e  its  root ;  aiul  by  that  dividing  the  subsequent  even  digit,  and  sub- 
tracting the  square  of  the  quotient  from  the  next  uneven  place,  note  in  a 
hne  [with  the  preceding  double  number]  the  double  of  the  quotient.  Divide 
by  tiie  [number  as  noted  in  a]  line  the  next  even  place,  and  deduct  the 
square  of  the  quotient  from  the  following  uneven  one,  and  note  the  double 
of  the  quotient  in  the  line.  Repeat  the  process  [until  the  digits  be  ex- 
hausted.]    Half  the  [number  noted  in  the]  line  is  the  root. 

22.  Example.  Tell  me,  dear  woman,  the  root  of  four,  and  of  nine,  and 
those  of  the  squares  before  found,  if  thy  knowledge  extend  to  this  calculation. 

Statement,  4,  9,  81,  196,  88209,  100100025. 
Answer.     The  roots  are  2,  3,  9,  14,  297,  10005. 

23 — 25.     Rule  for  the  cube' :  three  stanzas. 

The  continued  multiplication  of  three  like  quantities  is  a  cube.  The  cube 
of  the  last  [digit]  is  to  be  set  down;  and  next  the  square  of  the  last  multi- 
plied by  three  times  the  first ;  and  then  the  square  of  the  first  taken  into  the 
last  and  tripled;  and  lastly  the  cube  of  the  first:  all  these,  added  together 
according  to  their  places,  make  the  cube.  The  proposed  quantity  [consist- 
ing of  more  than  two  digits]  is  distributed  into  two  portions,  one  of  which  is 
then  taken  for  the  last  [and  the  other  for  the  first] ;  and  in  like  manner  re- 
peatedly [if  there  be  occasion.*]  Or  the  same  process  may  be  begun  from 
the  first  place  of  figures,  either  for  finding  the  cube,  or  the  square.  Or  three 
times  the  proposed  number,  multiplied  by  its  two  parts,  added  to  the  sum 
of  the  cubes  of  those  parts,  give  the  cube.  Or  the  square  root  of  the  pro-, 
posed  number  being  cubed,  that,  multiplied  by  itself,  is  the  cube  of  the  pro- 
posed square.' 


4;  thus,  58.  By  this  divic^  the  even  place  410;  the  quotient  is  7,  and  remainder  4y;  to  which 
uneven  digit  the  square  of  the  quotient  49  answers  without  residue.  The  double  of  the  quotient 
14  is  put  in  a  line  with  the  preceding  double  number  58,  making  594.  The  half  of  which  is  the 
root  sought,  297.  Mono,  and  Gang. 

'  G'hana,  a  cube.     {lit.  solid.) 

*  The  subdivision  is  continued  until  it  comes  to  single  digits. 

Gan'es'a  confines  it  to  the  places  of  figures  (st'h&iia-vibhdga,)  not  allowing  the  portioning  of  the 
number  (rupa-vibh6ga;)  because  the  addition  is  to  be  made  according  to  the  places.  ■ -'i 

'  This  carries. an  allusion  to  the  raising  of  quantities  to  higher  powers  than  the  cube.    Ok'sHa 


Sect.  II. 


LOGISTICS. 


11 


26.  Example.  Tell  me,  dear  woman,  the  cube  of  nine,  and  the  cube  of 
the  cube  of  three,  and  the  cube  of  the  cube  of  five,  and  the  cube-roots  of 
these  cubes,  if  thy  knowledge  be  great  in  computation  .of  cubes. 

Statem.ent,  9,  27,  125. 

Answer:  The  cubes  in  the  same  order,  are  729,  19683,  1953125.' 


The  proposed  number  being  nin^  and  its  parts  4  and  5.  Then  9  multi- 
plied by  them  and  by  three  is  540;  which,  added  to  the  sum  of  the  cubes 
64  and  125,  viz.  189,  makes  the  cube  of  nine  729- 

The  entire  number  being  27,  its  parts  are  20  and  7:  by  which,  the  nuin- 
ber  ^eing  successively  multiplied,  and  then  tripled,  is  1 1340;  and  this,  added 
to  the  sum  of  the  cubes  of  the  parts  8343,  makes  the  cube  19683. 

The  proposed  number  being  a  square,  as  4.  Its  root  2  cubed  is  8.  This, 
taken  into  itself,  gives  64  the  cube  of  four.  So  nine  being  proposed,  its 
square  root  3,  cubed,  is  27 ;  the  square  of  which  729  is  the  cube  of  9.  In 
short  the  square  of  the  cube  is  the  same  with  the  cube  of  the  square. 


\, 


•peciSes  some  of  them.  The  product  of  four  like  numbers  multiplied  together  is  the  square  of  a 
square,  varga-varga.  Continued  multiplication  up  to  six  is  the  cube  of  a  square,  or  square  of  a 
cube,  varga-g'/iana  or  g'hana-varga.  Continued  to  eight,  it  is  the  square  of  a  square's  square, 
targa-varga-varga.  Continued  to  nine,  it  is  the  cube  of  a  cube,  g'hana-g'hana.  Intermediately  are, 
the  fifth  power,  varga-g'hana-gh&ta ;  and  the  seventh,  varga-varga-g'/tana-ghdta. 

'  The  number  proposed  being  125,  distributed  into  two  parts  12  and  5;  and  the  first  of  these 
again  into  two  portions,  1  and  2 : 

Then  1,  cubed,  is 1 

1,  square  of  I,   tripled   and  multiplied  by  2, 6 

4,  square  of  2,  tripled  and  multiplied  by  1, 12 

2,  cubed, S 

1728 

Now     12,  cubed  as  above,  is 1728 

144,  square  of  12,  tripled  and  multiplied  by  5 2l60 

25,  square  of  5,  tripled  and  multiplied  by  12, 900 

5,  cubed, 125 

1953125 

Mono. 


C  2 


Ifi  LI'LAVATI'.  Chapter  II. 

27 — 28.     Rule  for  the  cube-root' :  two  stanzas. 

The  first  [digit]  is  a  cube's  place;  and  the  two  next  uncubic;  and  again, 
the  rest  in  like  manner.  From  the  last  cubic  place  take  the  [nearest]  cube, 
and  set  down  its  root  apart.  By  thrice  the  square  of  that  root  divide  the 
next  [or  uncubic]  place  of  figures,  and  note  the  quotient  in  a  line  [with  the 
quantity  before  found.]  Deduct  its  square  taken  into  thrice  the  last  [term,] 
from  the  next  [digit ;]  and  its  cube  from  the  succeeding  one.  Thus  the  line 
[in  which  the  result  is  reserved]  is  the  root  of  the  cube.  The  operation  is 
repeated  [as  necessary.]* 

Example.  Statement  of  the  foregoing  cubes  for  extraction  of  the  root: 
729,   19683,   1953125.' 

Answer.     The  cube-roots  respectively  are  9,  27,  125. 

'  G'hana-miila;  root  of  the  cube. 

*  The  same  rule  is  taught  by  Brahmegupta,  §  7,  and  Sri'd'hara,  §  29 — 31. 

'  The  mode  of  conducting  the  work  is  shown  in  the  Manoranjana,  viz.  1953125.     Here  the  last 

1 — I 

cubic  digit  is  1.     Subtracting  1  the  cube  of  the  number  1,  the  remainder  is  953125  ;  and  the 

root  obtained  is  1,  which  is  to  be  set  down  in  two  places.  Dividing  the  next  digit  by  three  times 
the  square  of  that,  the  quotient  taken  is  2  [for  3  would  soon  appear  to  be  too  great ;]  and  the  re- 
sidue is  353125  ;  and  the  quotient  2,  put  in  a  line  with  1,  makes  12.     Subtract  the  square  of  this 

2,  tripled  and  multiplied  by  the  last  term,  viz.  12,  from  the  next  digit,  the  remainder  is  233125; 

—  I 
and  the  cube  of  the  quotient  2,  viz.  8,  being  taken  from  the  succeeding  digit,  the  residue  is  225 125. 

Again,  the  reserved  root  12,  being  squared  and  tripled,  gives  432.    The  next  place  of  figures, 

divided  by  this,  yields  the  quotient  5  and  remainder  Q\Z5;  and  the  quotient  is  set  down  in  the 

line,  which  becomes  125.     The  square  of  that  5,  viz.  25,  multiplied  by  the  last  term  12,   is  300, 

and  tripled  900  ;  which  subtract  from  the  next  place,  and  the  residue  is  125.     Take  the  cube  of 

the  quotient  5,  viz.  125,  from  the  succeeding  digit,  and  the  remainder  is  0.    Thus  the  root  is 

found  125. 


I 


(     13     ) 


4  ' 


SECTION  III. 

FRACTIONS.' 

FOUR  RULES    FOR   THE    ASSIMILATION  OR   REDUCTION    OF    FRACTIONS    TO   A 

COMMON    DENOMINATOR.* 

Simple  Reduction  of  Fractions.* 

29-  Rule.  The  numerator  and  denominator*  being  multiplied  recipro- 
cally by  the  denominators  of  the  two  quantities,'  they  are  thus  reduced  to 
the  same  denomination.  Or  both  numerator  and  denominator  may  be  mul- 
tiplied by  the  intelligent  calculator  into  the  reciprocal  denominators  abridged 
by  a  common  measure. 

30.     Example.     Tell  me  the  fractions  reduced  to  a  common  denominator 


'  Bhinna  a  fraction  ;  lit.  a  divided  quantity,  or  one  obtained  by  division. — Gan.  An  incom- 
plete quantity  or  non-integer  (apurna). — Gang.  A  proper  or  improper  fraction,  including  a 
quantity,  to  which  a  part,  as  a  moiety,  a  quarter,  &c.  is  added ;  or  from  which  such  a  part  is 
deducted. — Gan.  , 

*  Bhuga-j&ti-chatushiaya,  J6t'i-chatushtaya,  or  four  modes  of  assimilation  or  process  for  reducing,  to 
a  common  denomination,  fractions  having  dissimilar  denominators :  preliminary  to  addition  and 
subtraction,  and  other  arithmetical  operations  upon  fractions.  Brahmegupta's  commentator 
Chaturve'da  carries  to  six  the  number  of  rules  termed _/<{<«,  assimilation,  or  reduction  to  uni- 
formity; and  Srio'hara  has  no  less  than  eight;  including  rules  answering  to  Bha'scara's  for 
the  arithmetic  of  fractions  (Lit.  \  36 — 43J,  and  for  the  solution  of  certain  problems  (Lil. 
§  52—54,  and  §  94— 95.J  See  Brahmegupta's  Arithmetic,  §  1,  note,  (and  §  2—5.  §  8— p.)  and 
Gaii.  s&r.  §  32—57. 

*  Bhiiga-jdti  or  Ansa-savarna,  assimilation  of  fractions ;  or  rendering  fractions  homogeneous : 
reduction  of  them  to  uniformity. 

*  BMga,  ansa,  vibMga,  lava,  &cc.  a  part  or  fraction :  the  numerator  of  a  fraction. 

Hara,  Mra,  ch'hida,  &c.  the  divisor ;  the  denominator  of  a  fraction.  That,  which  is  to  be  di- 
vided, is  the  part  (ansa)  ;  and  that,  by  which  it  is  to  be  divided,  is  (hara)  the  divisor.  Gan. 
and  SuR. 

'  EAU  a  quantity,  §  36.  It  here  intends  one  consisting  of  two  terms;  a  part  and  a  divisor,  or 
numerator  and  denominator.  Gamb.. 


14  LIXAVATI'.  Chapter  II. 

which  answer  to  three  and  a  fifth,  and  one-third,  proposed  for  addition  ;  and 
those  whicli  correspond  to  a  sixty-third  and  a  fourteenth  offered  for  sub- 
traction. 

Statement:  if  i-* 

Answer.     Reduced  to  a  common  denominator  ff  -^  -^.     Sum  -ff-. 

Statement  of  tlie  2d  example :  -jV  i^- 

Answer.  The  denominators  being  abridged,  or  reduced  to  least  terms,  by 
the  common  measure  seven,  the  fractions  become  -^  -^. 

Numerator  and  denominator,  multiplied  by  the  abridged  denominators, 
give  respectively  -j-a-«  a°d  -j-|-y. 

Subtraction  being  made,  the  difference  is  ^-f^. 


Reduction  of  subdivided  Fractions. 

SI.     Rule:  half  a  stanza.  ^ 

The  numerators  being  multiplied  by  the  numerators,  and  the  denomi- 
nators by  the  denominators,  the  result  is  a  reduction  to  homogeneous  form 
in  subdivision  of  fractions. 

32.  Example.  The  quarter  of  a  sixteenth  of  the  fifth  of  three-quarters 
of  two-thirds  of  a  moiety  of  a  dramma  was  given  to  a  beggar  by  a  person, 
from  whom  he  asked  alms :  tell  me  how  many  cowry  shells  the  miser  gave, 


•  Among  astronomers  and  other  arithmeticians,  oral  instruction  has  taught  to  place  the  nume- 
rator above  and  denominator  beneath.  Gan. 

No  line  is  interposed  in  the  original :  but  in  the  version  it  is  introduced  to  conform  to  the  prac- 
tice of  European  arithmetic.  Biia'scara  subsequently  directs  (§  36)  an  integer  to  be  written  as 
a  fraction  by  placing  under  it  unity  for  its  denominator.  The  same  is  done  by  him  in  this  place 
in  the  text.  It  corresponds'^with  the  directions  of  Srid'hara  and  of  Brahmegupta's  commen- 
tator.    Gan.  s6r.  §  32 ;  Brahm.  §  5. 

*  Prabh6ga^&ti  assimilation  of  sub-fraetions,  or  making, uniform  the  fraction  of  a  fraction:  it 
is  a  sort  of  division  of  fractions,  G\H, 

Trabhiga  a  divided  fraction,  or  fraction  of  a  fraction  ;  as  a  part  of  a  moiety,  and  so  forth. 

Gang. 
Chaturveda  terms  this  operation  Tratt/utpanna-juti ;  assimilation  consisting  in  multiplication, 
or  reduction  to  bomogeneousness  by  tnultiplication.    Brahm.  §  8. 


J> 


Sect.  III.  FRACTIONS.  15 

if  thou  be  conversant,  in  arithmetic,  with  the  reduction  termed  subdivision 
of  fractions. 

Statement  •  i  x  2.  i  x  _i_  i 

Reduced  to  homogeneousness  y^^,  or  in  least  terms  ^-jVo- 

Answer.     A  single  cowry  sbell  was  given.' 


Reduction  of  Quantities  increased  or  decreased  by  a  Fraction.^ 

35.     Rule :  A  stanza  and  a  half. 

The  integer  being  multiplied  by  the  denominator,  the  numerator  is  made 
positive  or  negative,'  provided  parts  of  an  unit  be  added  or  be  subtractive. 
But,  if  indeed  the  quantity  be  increased  or  diminished  by  a  part  of  itself, 
then,  in  the  addition  and  subtraction  of  fractions,  multiply  the  deno- 
minator by  the  denominator  standing  underneath,*  and  the  numerator  by 
the  same  augmented  or  lessened  by  its  own  numerator. 


'  For  a  cowry  shell  is  in  the  tale  of  money  the  1 280th  part  of  a  dramma,     §  2. 

*  Bhiganuband'ha-jati ;  assimilation  of  fractional  increase;  reduction  to  uniformity  of  an  in- 
crease by  a  fraction,  or  the  addition  of  a  part:  from  anuband^ha  junction — Gan'.,  union — Stfa., 
addition — Gang. 

Bhig6pax6ha-j/iti;  assimilation  of  fractional  decrease,  reduction  to  uniformity  of  a  decrease  by 
a  fraction,  or  the  subtraction  of  a  part :  derived  from  apavdha  deduction,  lessening,  or  subtrac- 
tion. 

These,  as  remarked  by  Ganb's'a,  are  sorts  of  addition  and  subtraction. 

The  fractions  may  be  parts  of  an  integer,  or  proportionate  parts  of  the  proposed  quantity  itself. 
Hence  two  sorts  of  each,  named  by  the  commentators  (Gang,  and  Sua.)  Ripa-bAdgdnuband'ha, 
addition  of  the  fraction  of  an  unit;  Rupa-bMg/tpavAha,  subtraction  of  the  fraction  of  an  unit; 
R&si'bhiganuband'ka,  addition  of  a  fraction  of  the  quantity;  Rdii-bltagdpaidha,  subtraction  of  a 
fraction  of  the  quantity. 

'  And  added  or  subtracted  accordingly.  See  explanation  of  positive  and  negative  quantity 
(d'haaa  and  rlna)  in  Vija-gamita,  §  3. 

♦  Indian  arithmeticians  write  fractions  under  the  quantities  to  which  they  are  additive,  or  from 
which  they  are  subtractive.  Accordingly,  '  the  numerators  and  denominators  are  put  in  their 
order,'  one  under  the  other.  Then  multiply  the  denominator  which  stands  above,  by  that  which 
stands  below  ;  and  the  upper  numerator,  by  a  multiplier  consisting  of  the  same  denominator  with 
its  own  numerator  added  or  deducted,  ttepeat  the  operatiom  till  the  up  and  down  line  cOnthin 
but  two  quantities.' — Sua. 

It  must  have  originally  contained  three  terms  or  numbers,  at  the  least,  in  examples  of  the 
first  rule;  and  four,  in  those  of  the  last. — Gang. 


16  LI'LA'VATI'.  Chapteb  II. 

34.  Example.  Say,  how  much  two  and  a  quarter,  and  three  less  a 
quarter,  are,  when  reduced  to  uniformity,  if  thou  be  acquainted  with  frac- 
tional increase  and  decrease. 

Statement:  2        3 

Answer :  Reduced  to  homogeneousness,  they  become  -J-  and  V . 

35.  Example.  How  much  is  a  quarter  added  to  its  third  part,  with  a 
quarter  of  the  sum  ?  and  how  much  are  two-thirds,  lessened  by  one-eighth 
of  them,  and  then  diminished  by  three-sevenths  of  the  residue  ?  Tell  me, 
likewise,  how  much  is  half  less  its  eighth  part,  added  to  nine-sevenths  of 
the  residue,  if  thou  be  skilled,  dear  woman,  in  fractional  increase  and  de- 
crease ? 

Statement:  i*  -I  i 

Answer :  Reduced  to  uniformity,  the  results  are  i  i  -f. 


The  Eight  Rules  of  Arithmetic  applied  to  Fractions.* 

56.    Rule  for  addition  and  subtraction  of  fractions  :*  half  a  stanza. 
The  sum  or  [in  the  case  of  subtraction]  the  difference  of  fractions  having 


*  Multiply  the  upper  denominator  4,  by  the  one  beneath,  3  ;  the  product  is  12.  Then,  by  the 
same  denominator  3  added  to  its  numerator  1,  making  4,  multiply  the  upper  numerator;  the 
product  is  4.  Again  multiply  the  denominator  as  above  found  by  the  lower  denominator  2,  the 
product  is  24 ;  and  by  the  same  added  to  its  numerator,  making  3,  multiply  the  numerator  before 
found,  viz.  4,  the  product  is  12.  The  result,  therefore,  is  ^;  which,  abridged  by  the  common 
divisor  six,  gives  ^  or  a  moiety.-.— Ma«d, 

*  Bkinna'paricarmdshtaca ;  the  eight  modes  of  process,  as  applicable  to  fractions  :  the  preceding 
section  being  relative  to  those  arithmetical  processes  as  applicable  to  whole  terras  (abhinna'fari- 
earmhhtacaj. 

*  Bhinna-sancalUa,  addition  of  fractions.    Bhinna-vt/avacaUta,  subtraction  of  fractions. 


Sect.  III. 


FRACTIONS. 


17 


a  common  denominator,    is  [taken].     Unity'  is  put  denominator  of  a  quan- 
tity' which  has  no  divisor.' 

ij.  Example.  Tell  me,  dear  woman,  quickly,  how  much  a  fifth,  a 
quarter,  a  third,  a  half,  and  a  sixth,  make,  when  added  together.  Say 
instantly  what  is  the  residue  of  three,  subtracting  those  fractions  ? 

Statement .-  -i  x  x  x  x. 

6      4     3      2      0 

Answer :  Added  together  the  sum  is  |-f . 

[Statement  A  i  J.  ii^.] 

Subtracting  those  fractions  from  three,  the  remainder  is  -f-x. 

38.     Rule  for  multiplication  of  fractions  :*  half  a  stanza. 
The  product  of  the  numerators,  divided  by  the  product  of  denominators, 
[gives  a  quotient,  Avhich]  is  the  result  of  multiplication  of  fractions. 

39-  Example.  What  is  the  product  of  two  and  a  seventh,  multiplied  by 
two  and  a  third?  and  of  a  moiety  multiplied  by  a  third.''  tell,  if  thou  be 
skilled  in  the  method  of  multiplication  of  fractions. 

Statement :  2  .  2  (or  reduced  i  .  y )  \  .  \. 

\_       X 

a        7 

Answer  :  the  products  are  \  and  \. 

40.  Rule  for  division  of  fractions  :'  half  a  stanza. 

After  reversing  the  numerator  and  denominator  of  the  divisor,  the  re- 
maining process  for  division  of  fractions  is  that  of  multiplication. 

41.  Example.     Tell  me  the  result  of  dividing  five  by  two  and  a  third; 


'  JRi/pa,  the  species  or  form ;  any  thing  having  bounds. — Gang.     Discrete  quantity.     In  the 
singular,  the  arithmetical  unit ;  in  the  plural,  integer  number.     See  Vija-gariita,  §4. 

*  Rdsi,  a  congeries;  a  heap  of  things,  of  which  one  is  the  scale  of  numeration ;  a  quantity  or 
number.     See  Vija-gan.  ib. 

*  That  is,  it  is  put  denominator  of  an  integer. 

*  Bhinm-gunana,  multiplication  of  fractions. 
'  Bhinnorblidga-hara  ;  division  of  fractions. 


18  LIXATATI.  Chapter  II. 

and  a  sixth  by  a  third ;  if  thy  understanding,  sharpened  into  confidence, 
be  competent  to  the  division  of  fractions. ' 


Statement:  2{i)i     i  i- 

i 
Answer :  Proceeding  as  directed,  the  quotients  are  y  and  -J-. 


42.  Rule  for  involution  and  evolution  of  fractions  :*  half  a  stanza. 

If  the  square  be  sought,  find  both  squares  ;  if  the  cube  be  required,  both 
cubes :  or,  to  discover  the  root  [of  cube  or  square,]  extract  the  roots  of 
both  [numerator  and  denominator]. 

43.  Example.  Tell  me  quickly  what  is  the  square  of  three  and  a  half; 
and  the  square  root  of  the  square  ;  and  the  cube  of  the  same ;  and  the  cube 
root  of  that  cube  :  if  thou  be  conversant  with  fractional  squares  and  roots  ? 

Statement :  3  or  reduced  -J-. 

X 

a 

Answer.  Its  square  is  V  j  of  which  the  square  root  is  ^.  The  cube  of 
it  is  »-|' ;  of  which  again  the  cube  root  is  i. 


•  Gan'esa  omits  the  latter  half  of  the  stanza.     Ganga'd'hara  gives  it  entire. 

*  Bhinnorvarga,  square  of  a  fraction ;  Bhinna-g'hana,  cube  of  a  fraction,  &c. 


(19    ) 


SECTION  IV. 


CIPHERS 

44 — 45.     Rule  for  arithmetical  process  relative  to  cipher :   two  couplets. 

In  addition,  cipher  makes  the  sum  equal  to  the  additive.*  In  involution 
and  [evolution]'  the  result  is  cipher.  A  definite  quantity/  divided  by  cipher, 
is  the  submultiple  of  nought.'  The  product  of  cipher  is  nought :  but  it 
must  be  retained  as  a  multiple  of  cipher,*  if  any  further  operation  impend. 
Cipher  having  become  a  multiplier,  should  nought  afterwards  become  a 
divisor,  the  definite  quantity  must  be  understood  to  be  unchanged.  So 
likewise  any  quantity,  to  which  cipher  is  added,  or  from  which  it  is  sub- 
tracted,   [is  unaltered.] 

46.  Example.  Tell  me  how  much  is  cipher  added  to  five  ?  and  the 
square  of  cipher?  and  its  square  root  ?  its  cube?  and  cube-root?  and  five 
multiplied  by  cipher?  and  how  much  is  ten,  subtracting  cipher?  and  what 


•  bunya,  c'ha,  and  other  synonyraa  of  vacuum  or  etherial  space :  nought  or  cipher;  a  blank 
or  the  privation  of  specific  quantity. — Crishn.  on  V'tja-gaiiita. 

The  arithmetic  of  cipher  is  briefly  treated  by  Brahmegupta  in  his  chapter  on  Algebra, 
h  19 — 24.     See  Cii.  on  Arithm.  of  Braiim.  §  13,  note. 

CshSpa;  that  which  is  cast  or  thrown  in  ('wAipj^afO  •  additive.  Gang. 

*  Involution,  &c.     That  is,  square  and  square-root ;  cube  and  cube-root.  Gang. 

♦  R/isi.     See  §  36. 

'  C'ha-hara,  a  fraction  with  cipher  for  its  denominator.  According  to  the  remark  of  Gan'e's'a, 
aa  indefinite,  unlimited,  or  infinite  quantity  :  since  it  cannot  be  determined  how  great  it  is.  Un- 
altered by  addition  or  subtraction  of  finite  quantities:  since,  in  the  preliminary  operation  of  re- 
ducing both  fractional  e.\pressions  to  a  common  denominator,  preparatory  to  taking  their  sum  or 
difference,  both  numerator  and  denominator  of  the  finite  quantity  vanish.  RanganaYha  affirms, 
that  it  is  infinite,  because  the  smaller  the  divisor  is,  the  greater  is  the  quotient :  now  cipher,  being 
in  the  utmost  degree  small,  gives  a  quotient  infinitely  great.     See  Vya-gadita,  §  14. 

*  Chaguiia,  a  quantity  which  has  cipher  for  its  multiplier.  Cipher  is  set  down  by  the  side  of 
the  multiplicand,  to  denote  it.  Gan. 


80  LIXAVATI'.  Chapter  II. 

number  is  it,  which  multiplied  by  cipher,  and  added  to  half  itself,  and  mul- 
tiplied by  three,  and  divided  by  cipher,  amounts  to  the  given  number  sixty- 
three  ? 

Statement :  0.  Cipher  added  to  five  makes  5.  Square  of  cipher,  0. 
Square-root,  0.     Cube  of  cipher,  0.     Cube-root,  0. 

Statement :   5.     This,  multiplied  by  cipher  makes  0. 

Statement:    10.     This,  divided  by  cipher,  gives  V*- 

Statement;  An  unknown  quantity;  its  multiplier,  0;  additive,  i;  mul- 
tiplicator,  3;  divisor,  0;  given  number,  63;  assumption,  1.  Then,  either 
by  inversion  or  position,  as  subsequently  explained  (§  47  and  50),  the  num- 
ber is  found,  14.  This  mode  of  computation  is  of  frequent  use  in  astrono- 
mical calculation. 


CHAPTER  HI. 


MISCELLANEOUS  RULES: 
SECTION  I. 

INVERSION. 

47 — 48.     Rule  of  inversion  :*   two  stanzas. 

To  investigate  a  quantity,  one  being  given,'  make  the  divisor  a  multi- 
plicator  :  and  the  multipher,  a  divisor ;  the  square,  a  root ;  and  the  root,  a 
square  ;*  turn  the  negative  into  positive ;  and  the  positive  into  negative. 
If  a  quantity  was  to  be  increased  or  diminished  by  its  own  proportionate 
part,  let  the  [lower']  denominator,  being  increased  or  diminished  by  its  nu- 
merator, become  the  [corrected']  denominator,  and  the  numerator  remain 
unchanged  ;  and  then  proceed  with  the  other  operations  of  inversion,  as  be- 
fore directed. 

49.  Example.  Pretty  girl  with  tremulous  eyes,  if  thou  know  the  cor- 
rect method  of  inversion,  tell  me,  what  is  the  number,  which  multiplied  by 

'  Pracirna  miscellaneous.  The  rules,  contained  in  the  five  first  sections  of  this  chapter,  have 
none  answering  to  them  in  the  Arithmetic  of  Brahmegupta  and  Sri'd'hara.  Some  of  the  ex- 
amples, however,  serving  to  illustrate  the  reduction  of  fractions  (as  §  51 — 54.)  do  correspond. 
Compare  §  54  with  Gari.  sdr.  §  52. 

*  Viloma-vid'hi,  Viluma-criyd,  Vyasta-vid'hi,  inversion. 

'  Drisya;  the  quantity  or  number,  which  is  visible  ;  the  one  known  by  the  enunciation  of  the 
problem  :  the  given  quantity. 

♦  And  the  cube,  a  cube-root ;  and  the  cube-root,  a  cube.  Gan'. 
'  Ganga'd'hara. 


32  LI'LA'VATI'.  Chapter  III. 

three,  and  added  to  three  quarters  of  the  quotient,  and  divided  by  seven, 
and  reduced  by  subtraction  of  a  third  part  of  the  quotient,  and  then  multi- 
pUed  into  itself,  and  having  fifty-two  subtracted  from  the  product,  and  the 
square  root  of  the  remainder  extracted,  and  eight  added,  and  the  sum  divided 
by  ten,  yields  two  ? ' 

Statement :  Multiplier  3.  Additive  \.  Divisor  7.  Decrease  i-  Square 
— .  Subtractive  52.  Square-root  — .  Additive  8.  Divisor  10.  Given 
number  2. 

Answer.    Proceeding  as  directed,  the  result  is  28 ;  the  number  sought. 


•  All  the  operations  are  inverted.  The  known  number  2,  multiplied  by  the  divisor  10  con- 
verted into  a  multiplicator,  makes  20;  from  which  the  additive  8,  being  subtracted,  leaves  12; 
the  square  whereof  (extraction  of  the  root  being  directed)  is  144;  and  adding  the  subtractive  52, 
becomes  196:  the  root  of  this  (squaring  was  directed)  is  14 :  added  to  its  half,  7,  it  amounts  to 
21 ;  and  multiplied  by  7,  is  147.  This  again  divided  by  7  and  multiplied  by  3,  makes  63 ;  which, 
subtracted  from  147,  leaves  84 ;  and  this,  divided  by  3,  gives  28.  Maao. 


(   23    )  BI- 

SECTION II. 

SUPPOSITION. 

50.  Rule  of  supposition  :•  one  stanza. 

Or  any  number,  assumed  at  pleasure,  is  treated  as  specified  in  the  parti- 
cular question ;  being  multiplied  and  divided,  raised  or  diminished  by  frac- 
tions :  then  the  given  quantity,  being  multiplied  by  the  assumed  number 
and  divided  by  that  [which  has  been  found,]  yields  the  number  sought. 
This  is  called  the  process  of  supposition.* 

51.  Example.'  What  is  that  number,  which  multiplied  by  five,  and 
having  the  third  part  of  the  product  subtracted,  and  the  remainder  divided 
by  ten,  and  one-third,  a  half  and  a  quarter  of  the  original  quantity  added, 
gives  two  less  than  seventy  ? 

Statement :  Mult.  5.  Subtractive  ^  of  itself  Div.  10.  Additive  i -i  i 
of  the  quantity.     Given  68. 

Putting  3;  this,  multiplied  by  5,  is  15  ;  less  its  third  part,  is  10;  divided 
by  ten,  yields  1.  Added  to  the  third,  half  and  quarter  of  the  assumed 
number  three,  viz.  ^^j^,  the  sum  is  V-  ^y  this  divide  the  given  number 
68  taken  into  the  assumed  one  3 ;   the  quotient  is  48. 

The  answer  is  the  same  with  any  other  assumed  number,  as  one,  &c. 

•  Thus,  by  whatever  number  the  quantity  is  multiplied  or  divided  in  any 
example,  or  by  whatever  fraction  of  the  quantity,  it  is  increased  or  dimi- 
nished;   by  the  same  should  the  like  operations  be  performed  on  a  number 

■  Iskia-carman :  operation  with  an  assumed  number.  It  is  the  rule  of  false  position,  suppo- 
sition, and  trial  and  error. 

In  this  method,  multiplication,  division,  and  fractions  only  are  employed.  Gan. 

'  Reduction  of  a  given  number  with  affirmative  fractions  is  the  subject  of  this  example;  as  re- 
duction of  a  number  given,  with  negative  fractions,  is  that  of  the  next.  Sua. 

In  the  rule  of  position  or  reduction  appertaining  to  it,  are  comprehended  reduction  of  given 
quantity  (with  fractions  affirmative  or  negative),  reduction  of  fractions  of  residues,  and  reduction 
of  differences  of  fractions.  Gako. 


24  LI'LA'VATr.  Chapter  III. 

arbitrarily  assumed :   and  by  that,  which  results,  divide  the  given  number 
taken  into  the  assumed  one  ;   the  quotient  is  the  quantity  sought. 

52.  Example  of  reduction  of  a  given  quantity.'  Out  of  a  heap  of  pure 
lotus  flowers,  a  third  part,  a  fifth  and  a  sixth,  were  offered  respectively  to 
the  gods  Siva,  Vishnu  and  the  Sun;  and  a  quarter  was  presented  to  Bha- 
va'ni.  The  remaining  six  lotuses  were  given  to  the  venerable  preceptor. 
Tell  quickly  the  whole  number  of  flowers. 

Statement :  -J-  y  i  i ;  known  6. 

Putting  one  for  the  assumed  number,  and  proceeding  as  above,  the  quan- 
tity is  found  120. 

53.  Example  of  reduction  of  residues  :*  A  traveller,  engaged  in  a  pil- 
grimage, gave  half  his  money  at  Prayaga;  two-ninths  of  the  remainder  at 
Casi;  a  quarter  of  the  residue  in  payment  of  taxes  on  the  road;  six-tenths 
of  what  was  left  at  Gaya  ;  there  remained  sixty-three  nishcas  ;  with  which 
he  returned  home.  Tell  me  the  amount  of  his  original  stock  of  money,  if 
you  have  learned  the  method  of  reduction  of  fractions  of  residues. 

Statement :  i  -|  i  ^  ;  known  63. 

Putting  one  for  the  assumed  number;  subtracting  the  numerator  from  its 
denominator,  multiplying  denominators  together,  and  in  other  respects 
proceeding  as  directed,  the  remainder  is  found  -^.  By  this  dividing  the 
given  number  63  taken  into  the  assumed  quantity,  the  original  sum  comes 
out  540. 

Or  it  may  be  found  by  the  method  of  reduction  of  fractional  decrease 
[§33].  Statement:  -i- -i«  .^^  h*  f]".  Being  reduced  to  homogeneous  form, 
the  result  is  -^  :  Avhence  the  sum  is  deduced  540. 

Or  this  may  also  be  found  by  the  rule  of  inversion  [§  47.] 

54.  Example  of  reduction  of  differences.'     Out  of  a  swarm  of  bees,  one- 


"  Drtiya-jiti ;  assimilation  of  the  visible;  reduction  of  the  given  quantity  with  fractions  affir- 
mative or  negative  :  here,  with  negative  ;   in  the  preceding  example,  with  affirmative. 

*  Skha-j&ti,  assimilation  of  residue;  reduction  of  fractions  of  residues  or  successive  fractional 
remainders. 

'  Viilisha-Jdti,  assimilation  of  difference  ;  reduction  of  fractional  differences. 


Sectiox  II. 


SUPPOSITION. 


25 


fifth  part  settled  on  a  blossom  of  Cadamba  ;'  and  one-third  on  a  flower  of 
Silind'hri  .-^  three  times  the  difference  of  those  numbers  flew  to  the  bloom  of 
a  CuiaJaJ  One  bee,  which  remained,  hovered  and  flew  about  in  the  air, 
allured  at  the  same  moment  by  the  pleasing  fragrance  of  a  jasmin  and  pan- 
danus.     Tell  me,  charming  woman,  the  number  of  bees.* 


Statement :  x  x  ^ ;  known  quantity,  1  ;  assumed,  30. 

A  fifth  of  the  assumed  number  is  6;  a  third  is  10;  difi^erence  4  ;  multi- 
plied by  three  gives  12  ;  and  the  remainder  is  2.  Then  the  product  of  the 
known  quantity  by  the  assumed  one,  being  divided  by  this  remainder,  shows 
the  number  of  bees  15. 

Here  also  putting  unit  for  the  assumed  quantity,  the  number  of  the  swarm 
is  found  15. 

So  in  other  instances  likewise.* 


*  Cadamba,  Nauclea  orientalis  or  N.  Cadamba. 

*  Silind'hri,  a  plant  resembling  the  Cachora.     Crishx.  on  Vija-gari. 
■*,  Echites  antidysenterica. 

*  See  the  same  example  in  Vija-gaiiila,  §  108. 

'  The  Manoranjana  introduces  one  more  example,  which  is  there  placed  after  the  second.  It 
is  similar  to  one  which  occurs  in  Sri'd'hara's  Ga'nita-sdra,  §  30;  and  is  here  subjoined  : — "  The 
third  part  of  a  necklace  of  pearls,  broken  in  an  amorous  struggle,  fell  to  the  ground:  its  fifth 
part  rested  on  the  couch ;  the  sixth  part  was  saved  by  the  wench  ;  and  the  tenth  part  was  taken 
up  by  her  lover  :  six  pearls  remained  strung.   Say,  of  how  many  pearls  the  necklace  was  composed." 

Statement :  i  i  i -^  i  Rem.  6.    Answer  30. 


(     2ff    ) 


SECTION  III.' 

£5.     Rule  of  concurrence :  half  a  stanza. 

The  sum  with  the, difference  added  and  subtracted,  being  halved,  gives 
the  two  quantities.     This  is  termed  concurrence.* 

56.  Example.  Tell  me  the  numbers,  the  sum  of  which  is  a  hundred  and 
one ;  and  the  difference,  twenty-five  ;  if  thou  know  the  rule  of  concurrence, 
dear  child. 

Statement:  Sum  101;  diff.  25. — Answer:  the  two  numbers  are  38  and 
63. 

67'     Rule  of  dissimilar  operation  :J  half  a  stanza. 

The  difference  of  the  squares,  divided  by  the  difference  of  the  radical 
quantities,*  gives  their  sum  :  whence  the  quantities  are  found  in  the  mode 
before  directed. 

58.  Example.  Tell  me  quickly,  skilful  calculator,  what  numbers  are 
they,  of  which  the  difference  is  eight,  and  the  difference  of  squares  four 
hundred  ? 

Statement :  Diff.  of  the  quantities  8.     Diff.  of  the  squares  400. 
Answer.     The  numbers  are  2 1  and  29. 


•  The  rules  coraprised  in  this  section  are  treated  under  the  same  ti  ties  (Sancramaria  and  Vishama- 
carman)  by  Brahmegupta,  in  his  chapter  on  Algebra,  or,  as  by  him  termed,  lecture  on  the 
pulverizer,  §  25.     See  Chaturveda  on  Arithm.  of  Brahm.  §  66. 

•  Sancramana,  concurrence  or  mutual  penetration  in  the  shape  of  sum  and  difference. — Gang. 
Investigation  of  two  quantities  concurrentor  grown  together  in  form  of  sum  and  difference. — Gan. 
Calculation  of  quantities  latent  within  those  exhibited. — Sua.  The  same  term  signifies  transition 
(or  transposition).    See  Brahmegupta,  Arithm.  §  12. 

•  Vishama-carman :  the  finding  of  the  quantities,  when  the  difference  of  their  squares  is  given, 
and  either  the  sum  or  the  difference  of  the  quantities. — Gan.  A  species  of  concurrence.— Gang. 
See  below  LiUvati,  §  135.     Vija-gan.  %  148. 

•  Or  divided  by  their  sum,  gives  their  difference. — Gan. 


(    27    ) 


SECTION  IV. 


Problem  concerning  Squares.* 

A  certain  problem  relative  to  squares  is  propounded  in  the  next  instance. 

59 — 60  Rule:  The  square  of  an  arbitrary  number,  multiplied  by  eight  and 
lessened  by  one,  then  halved  and  divided  by  the  assumed  number,  is  one 
quantity:  its  square,  halved  and  added  to  one,  is  the  other.  Or  unity, 
divided  by  double  an  assumed  number  and  added  to  that  number,  is  a  first 
quantity ;  and  unity  is  the  other.  These  give  pairs  of  quantities,  the  sum 
and  difference  of  whose  squares,  lessened  by  one,  are  squares. 


Tell  me,  my  friend,  numbers,  the  sum  and  difference  of  whose  squares, 
less  one,  afford  square  roots :  which  dull  smatterers  in  algebra  labor  to  excru- 
ciate, puzzling  for  it  in  the  six-fold  method  of  discovery  there  taught.* 

To  bring  out  an  answer  by  the  first  rule,  let  the  number  put  be  i.  Its 
square,  \,  multiplied  by  eight,  is  2 ;  which,  lessened  by  one,  is  1.  This  halved 
is  i,  and  divided  by  the  assumed  number  (i)  gives  -^  for  the  first  quantity. 
Its  square  halved  is  i;  which,  added  to  one,  makes  f.  Thus  the  two 
quantities  are  i  and  f . 

So,  putting  one  for  the  assumed  number,  the  numbers  obtained  are  ^,  and 
y.     With  the  supposition  of  two,  they  are  V  ^"d  W* 

By  the  second  method,  let  the  assumed  number  be  1.  Unity  divided  by 
the  double  of  it  is  -i,  which,  added  to  the  assumed  number,  makes  -f-.  The 
first  quantity  is  thus  found.  The  second  is  unity,  1.  With  the  supposition 
of  two,  the  quantities  are  -J  and  4-.     Putting  three,  they  are  y  and  i. 


6 1 .     Another  Rule :'  The  square  of  the  square  of  an  arbitrary  number,  and 


•  Varga-carman.       Operation    relative    to    squares.     An  indeterminate  problem;    admitting 
innumerable  solutions. 

This  question,  found  in  some  copies  of  the  text,  and  interpreted  by  Ganga'd'hara  and  the 
Manoranjana,  is  unnoticed  by  other  commentators. 

•  To  bring  out  answers  in  whole  numbers :  the  two  preceding  solutions  giving  fractions. 

E  3  Gan.  and  Si;k. 


88  Ll'LA'VATI.  Chaptkr  III. 

the  cube  of  that  number,  respectively  multiplied  by  eight,  adding  one  to 
the  first  product,  are  such  quantities  ;i    equally  in  arithmetic  and  in  algebra. 

Put -J-.  The  square  of  the  square  of  the  assumed  number  is  -Jj-;  which, 
multiplied  by  eight,  makes  ^.  This,  added  to  one,  is  |;  and  is  the  first 
quantity.  Again  put  -f-.  Its  cube  is  i;  which,  multiplied  by  eight,  gives 
the  second  quantity  -l.  Next,  supposing  one,  the  two  quantities  are  9  and  8. 
Assuming  two,  they  are  129  and  64.  Putting  three,  they  are  649  and  216. 
And  so  on,  without  end,  by  means  of  various  suppositions,  in  the  several 
foregoing  methods. 

"  Algebraic  solution,  similar  to  arithmetical  rules,  appears  obscure ;  but  is 
not  so,  to  the  intelligent :  nor  is  it  sixfold,  but  manifold." 

*  The  greater  quantity  is  to  be  taken  such,  that  the  square  of  it  may  consist  of  three  portions, 
whereof  one  shall  be  unity;  and  the  remaining  two  be  squares;  and  twice  the  product  of  the 
.roots  of  those  squares  constitute  a  square,  the  root  of  which  will  be  the  second  quantity. 

Rang. 


(    29    ) 


SECTION   V. 

62—63.     Rule  for  assimilation  of  the  root's  coefficient  :*  two  stanzas. 

The  sum  or  difference  of  a  quantity  and  of  a  multiple  of  its  square-root 
being  given,  the  square  of  half  the  coefficient*  is  added  to  the  given  number; 
and  the  square  root  of  their  sum  [is  extracted  :  that  root,]  with  half  the 
coefficient  added  or  subtracted,  being  squared,  is  the  quantity  sought  by 
the  interrogator.'  If  the  quantity  have  a  fraction  added,  or  subtracted, 
divide  the  number  given  and  the  multiplicator  of  the  root,  by  unity  increased 
or  lessened  by  the  numerator,  and  the  required  quantity  may  be  then 
discovered,  proceeding  with  those  quotients  as  above  directed. 

A  quantity,  increased  or  diminished  by  its  square-root  multiplied  by  some 
number,  is  given.  Then  add  the  square  of  half  the  multiplier  of  the  root 
to  the  given  number:  and  extract  the  square-root  of  the  sum.  Add  half 
the  multiplier,  if  the  difference  were  given  ;  or  subtract  it,  if  the  sum  were 
so.     The  square  of  tlie  result  will  be  the  quantity  sought. 

64.  Example  (the  root  subtracted,  and  the  difference  given).  One 
pair  out  of  a  flock  of  geese  remained  sporting  in  the  water,  and  saw  seven 
times  the  half  of  the  square-root  of  the  flock  proceeding  to  the  shore  tired 
of  the  diversion.     Tell  me,  dear  girl,  the  number  of  the  flock. 

'  Mula-jdti,  mula-gunaca-j6ti  or  Ishta-mulinsa-j&ti,  assimilation  and  reduction  of  the  root's 
coefficient  with  a  fraction. 

Guna,  multiplicator  ;  7na/a-o^««'a,  root's  multiplier;  the  coefficient  of  the  root. 

'  The  quantity  sought  consists  of  two  portions  ;  one  the  square-root  taken  into  its  multiplicator; 
the  other  the  given  number.  The  number  givea  too  is  the  quantity  required  less  the  root  taken 
into  its  multiplicator  :  and  the  quairtity  sought  is  the  square  of  that  root.  Therefore  the  number 
given  is  one  that  consists  of  two  portions;  viz.  the  square  of  the  root  less  the  root  taken  into  its 
multiplier.  Now  the  root  taken  into  its  multiplier  is  equivalent  to  twice  the  product  of  the  root 
by  half  the  multiplicator.  By  adding  then  the  square  of  half  the  multiplicator  to  the  given 
number,  a  quantity  results  of  which  the  root  may  be  taken  ;  and  this  root  is  the  root(of  the  quantity 
sought)  less  half  the  multiplier.  Therefore  that  added  to  half  the  multiplier  is  the  root  (of  th» 
quantity  required)  ;  and  its  square,  of  course,  is  the  number  sought.  Rang. 


30  LI'LA'VATI'.  Chapter  III. 

Statement:  CoefF.  i.  Given  2.  Half  the  coefficient  is  i.  Its  square 
^ ;  added  to  the  given  number,  makes  -f-^ ;  the  square  root  of  which  is  -J. 
Half  the  coefficient  being  added,  the  sum  is  V;  or.  reduced  to  least  terms,  4. 
This  squared  is  16  ;  the  number  of  the  flock,  as  required. 

65.  Example  (the  root  added  and  the  sum  given).  Tell  me  what  is 
the  number,  which,  added  to  nine  times  its  square-root,  amounts  to  twelve 
hundred  and  forty  ? 

Statement:    CoefF.  g.     Given  1240.     Answer 96 1. 

66.  Example  (the  root  and  a  fraction  both  subtracted).  Of  a  flock  of 
geese,  ten  times  the  square-root  of  the  number  departed  for  the  M&nasa 
lake,*  on  the  approach  of  a  cloud :  an  eighth  part  went  to  a  forest  of 
St'halapadminis  :*  three  couples  were  seen  engaged  in  sport,  on  the  water 
abounding  with  delicate  fibres  of  the  lotus.  Tell,  dear  girl,  the  whole 
number  of  the  flock. 

Statement:    Coeff.  10.     Fraction  i.     Given  6. 

By  the  [second]  rule  (§  63) ;  unity,  less  the  numerator  of  the  fraction,  is 
i;  and  the  coefiicient  and  given  number,  being  both  divided  by  that,  become 
%^  and  y;  and  the  half  coefficient  is  %s.  With  these,  proceeding  by  the 
[first]  rule  (§  62),  the  number  of  the  flock  is  found  144. 

67.  Example.'  The  son  of  Prit'ha,*  irritated  in  fight,  shot  a  quiver 
of  arrows  to  slay  CARisrA.  With  half  his  arrows,  he  parried  those  of  his 
antagonist;  with  four  times  the  square-root  of  the  quiver-full,  he  killed  his 


;  '.•*  Wild  geese  are  observed  to  quit  the  plains  of  India,  at  the  approach  of  the  rainy  season ;  and 
the  lake  called  MAnasar&car  (situated  in  the  Un-  or  H&n-des)  is  covered  with  water-fowl,  geese 
especially,  during  that  season.  The  Hindus  suppose  the  whole  tribe  of  geese  to  retire  to  the  holy 
lake  at  the  approach  of  rain.    The  bird  is  sacred  to  Brahma. 

*  The  plant  intended  is  not  ascertained.    The  context  would  seem  to  imply  that  it  is  arboreous : 
as  the  term  signifies  forest. 

*  This  example  is  likewise  inserted  in  the  Vija-ganila,  §  133. 

*  AajuNA,  sunmmed  Part'ha  :  his  matronymic  from  Puit'ha  or  Kont'hi. 


Sect.  V. 


MISCELLANEOUS. 


31 


hbrses ;  with  six  arrows,  he  slew  Salya  ;'  with  three  he  demohshed  the 
umbrella,  standard  and  bow;  and  with  one,  he  cut  off  the  head  of  the 
foe.     How  many  were  the  arrows,  Avhich  Arjuna  let  fly  ? 

Statement :     Fraction  i.     Coeff.  4.     Given  10. 

The  given  number  and  coefficient  being  divided  (by  unity  less  the  fraction) 
become  20  and  8 ;  and  proceeding  by  the  rule  (§  63),  the  number  of  arrows 
comes  out  100. 

68.  Example.*  The  square-root  of  half  the  number  of  a  swarm  of  bees 
is  gone  to  a  shrub  of  jasmin ;'  and  so  are  eight-ninths  of  the  whole  swarm; 
a  female  is  buzzing  to  one  remaining  male  that  is  humming  within  a  lotus, 
in  which  he  is  confined,  having  been  allured  to  it  by  its  fragrance  at  night* 
Say,  lovely  woman,  the  number  of  bees. 

Here  eight-ninths  of  the  quantity,  and  the  root  of  its  half,  are  negative 
[and  consequently  subtractive]  from  the  quantity  :  and  the  given  number  is 
two  of  the  specific  things.  The  negative  quantity  and  the  number  given, 
being  halved,  bring  out  half  the  quantity  sought.'     Thus, 


Statement :     Fraction  f .     CoefF.  "^      Given  f. 

A  fraction  of  half  the  quantity  is  the  same  with  half  the  fraction  of  the 
quantity :  the  fraction  is  therefore  set  down  [unaltered]. 

Here,  proceeding  as  above  directed,  there  comes  out  half  the  quantity,  36; 
which,  being  doubled,  is  the  number  of  bees  in  the  swarm,  72. 

69-     Example.    Find  quickly,  if  thou  have  skill  in  arithmetic,  the  quantity, 


'  One  of  the  Cauraxas,  and  charioteer  of  Cakna. 

*  Inserted  also  in  the  Vija-ganiia.  §  132. 
'  Malati,  Jasminum  grandiflorum. 

♦  The  lotus  being  open  at  night  and  closed  in  the  day,  the  bee  might  be  caught  in  it.       Gan. 

'  In  such  questions,  it  is  necessary  to  observe  whether  the  coefficient  of  the  root  be  so  of  the 
root  of  the  whole  number,  or  of  that  of  its  part.  For  that  quantity  is  found,  of  whose  root  the 
coefficient  is  used.  But,  in  the  present  case,  the  root  of  half  the  quantity  is  proposed ;  and 
accordingly,  the  half  of  the  quantity  will  be  found  by  the  rule.  The  number  given,  however,  belongs 
to  the  entire  quantity.  Therefoia^  taking  half  the  given  number,  half  the  required  number  is 
to  be  brought  out  by  the  process  before  directed. 

Man6.  and  Sv'ri 


52  LI'LA'VATI'.  Chapter  III. 

which  added  to  its  third  part  and  eighteen  times  its  square  root,  amounts 
to  twelve  hundred. 

Statement:     Fraction -|^.     CoefF.  18.     Given  1200. 

Here,  dividing  the  coefficient  and  given  number  by  unity  added  to  the 
fraction  [§  63]  and  proceeding  as  before  directed,  the  number  is  brought 
out,  576. 


(     33     ) 


SECTION    VI. 

RULE  of  PROPORTION.' 

70.  Rule  of  three  terms.' 

The  first  and  last  terms,  which  are  the  argument  and  requisition,  must  be 
of  like  denomination ;  the  fruit,  which  is  of  a  different  species,  stands 
between  them :  and  that,  being  multiplied  by  the  demand  and  divided  by 
the  first  term,  gives  the  fruit  of  the  demand.'  In  the  inverse  method,  the 
operation  is  reversed.* 

71.  Example.  If  two  and  a  half  palas  of  saffron  be  obtained  for  three- 
sevenths  of  a  nishca ;  say  instantly,  best  of  merchants,  how  much  is  got  for 
nine  nishcas  ? 

Statement :  -f  4  f  •     Answer :  52  palas  and  2  carshas. 

72.  Example.  If  one  hundred  and  four  nishcas  are  got  for  sixty-three 
palas  of  best  camphor,  consider  and  tell  me,  friend,  what  may  be  obtained 
for  twelve  and  a  quarter  palas  ? 

Statement:  63  104  V-  Answer:  20  nishcas,  3  drammas,  8  panas,  3 
cacinis,   1 1  cowryshells  and  ^th  part. 

73.  Example.  If  a  chart  and  one  eighth  of  rice,  may  be  procured  for 
two  drammas,  say  quickly  what  may  be  had  for  seventy  pa/ias  ? 

'  The  rule  of  proportion,  direct  and  inverse,  simple  and  compound,  including  barter,  has  been 
similarly  treated  by  Brahmegupta,  Arithm.  §  10 — 13;  and  by  Srid'hara  (adding,  however, 
as  a  distinct  article,  the  sale  of  live  animals  and  slaves,  which  Bha'scara  places  under  the  rule  of 
three  invei-se).     Gad.  stir.  §  58—90. 

Trairdsica,  calculation  belonging  to  a  set  of  three  terms. — Gang.     Rule  of  three. 

The  first  term  is  pramiiia,  the  measure  or  argument ;  the  second  is  its  fruit,  phala,  or  produce  of 
the  argument ;  the  third  is  ich'h6,  the  demand,  requisition,  desire  or  question.  Gan. 

*  Ich'hd-phala,  produce  of  the  requisition,  or  fruit  of  the  question :  it  is  of  the  same  denomination 
or  species  with  the  second  term. 

♦  See  S  74. 

T 


34  LI'LAVAT'I.  Chapter  III. 

Statement  (reducing  drammas  to  panas) :    32  f  70. 
Answer :     2  charts,  7  drdnas,  1  adhaca,  2 prast'has. 

74.  Rule  of  three  inverse' 

If  the  fruit  diminish  as  the  requisition  increases,  or  augment  as  that 
decreases,  they,  who  are  skilled  in  accounts,  consider  the  rule  of  three  terms 
to  be  inverted.* 

When  there  is  diminution  of  fruit,  if  there  be  increase  of  requisition,  and 
increase  of  fruit  if  there  be  diminution  of  requisition,  then  the  inverse  rule 
of  three  is  [employed].     For  instance, 

75.  When  the  value  of  living  beings'  is  regulated  by  their  age;  and  in 
the  case  of  gold,  where  the  weight  and  touch*  are  compared;  or  when 
heaps'  are  subdivided  ;  let  the  inverted  rule  of  three  terms  be  [used]. 

76.  Example.  If  a  female  slave  sixteen  years  of  age,  bring  thirty-two 
\jiishcas],  what  will  one  aged  twenty  cost?  If  an  ox,  which  has  been  worked 
a  second  year,  sell  for  four  nishcas,  what  will  one,  which  has  been  worked 
six  years,  cost  ? 


1st  Qu. 

Statement : 

16  32  20. 

Answer :  25-f-  nishcas. 

2d  Qu. 

Statement : 

2     4     6. 

Answer:    1^  nishca. 

77.     Example.     If  a  gadymaca  of  gold  of  the  touch  of  ten  may  be  had 


'  Vyasta-trair&sica  or  Viloma-trtdrdsica,  rule  of  three  terms  inverse. 

*  The  method  of  performing  the  inverse  rule  has  been  already  taught  (§  70).  "  In  the  inverse 
method,  the  operation  is  reversed."  That  is,  the  fruit  is  to  be  multiplied  by  the  argument  and 
divided  by  the  demand.  Su'r. 

When  fruit  increases  or  decreases,  as  the  demand  is  augmented  01  diminished,  the  direct  rule 
(crama-trair&sica)  is  used.     Else  the  inverse.  Gan. 

'  Slaves  and  cattle.     The  price  of  the  older  is  less  ;  of  the  younger,  greater.     Gang,  and  Su'r. 

*  Colour  on  the  touchstone.     See  Alligation,  §  101. 

'  See  Chap.  10.  When  heaps  of  grain,  which  had  been  meted  with  a  small  measure,  are  again 
meted  with  a  larger  one,  the  number  decreases  ;  and  when  those,  which  had  been  meted  with  a 
large  measure,  are  again  meted  with  a  smaller  one,  there  is  increase  of  number.     Gang  and  Sue. 


Skctiox  VI.  RULE  OF  PROPORTION.  35 

for  one  nishca   [of  silver],  what  weight  of  gold  of  fifteen  touch  may  be 
bought  for  the  same  price  ? 

Statement:   10     1      15.     Answer  i. 

78.  Example.  A  heap  of  grain  having  been  meted  with  a  measure 
containing  seven  ad'hacas,  if  a  hundred  such  measures  were  found,  what 
would  be  the  result  with  one  containing  five  ad'hacas? 

Statement:  7     100    5.     Answer  140. 

79-     Rule  of  compound  proportion.* 

In  the  method  of  fi\-e,  seven,  nine  or  more '  terms,  transpose  the  fruit  and 
divisors;'  and  the  product  of  multiplication  of  the  larger  set  of  terms,  being 
divided  by  the  product  of  the  less  set  of  terms,*  the  quotient  is  the  produce 
[sought]. 


•  This,  which  is  the  compound  rule  of  three,  coraprises,  according  to  the  remark  of  Gau'e'sa, 
two  or  more  sets  of  three  terms  CtrairdsicaJ  ;  or  two  or  more  proportions  fanupdtaj,  as  Su'ryada'sa 
observes.  "Thus  the  rule  of  five  (pancha-r&sica)  comprises  two  proportions;  that  of  seven 
Ctapta-rdsicaJ,  three;  that  of  nine  (naca-riika),  four;  and  that  of  eleven  (ec&dasa-rdsica) ,  five." 

*  Meaning  eleven. — Mono.  Eleven  or  more. — Sua.  It  is  a  rule  for  finding  a  sixth  term,  five  being 
given;  (or,  from  seven  known  terms,  an  eighth  ;  from  nine,  a  tenth  ;    from  eleven,  a  twelfth). 

'  Ganbs'a  and  the  commentator  of  the  VdsanA  understand  this  last  word  (ch'hid  divisor)  at 
relating  to  denominators  effractions;  and  the  transposing  of  them  (if  any  there  be)  is  indeed  right: 
accordingly  the  author  gives,  under  this  rule,  an  example  of  working  with  fractions  (§  81).  But 
the  Manoranjana  and  Su'ryada'sa  explain  it  otherwise ;  and  the  latter  cites  an  ancient  commentary 
entitled  Gatiita-caumudi  (also  quoted  by  Rangan  at'ii  a)  in  support  of  his  exposition.  '  There  are 
two  sets  of  terms;  those  which  belong  to  the  argument;  and  those  which  appertain  to  the  requisition. 
The  fruit,  in  the  first  set,  is  called  produce  of  the  argument;  that,  in  the  second,  is  named  divisor 
of  the  set.  They  are  to  be  transposed,  or  reciprocally  brought  from  one  set  to  the  other.  That 
is,  put  the  fruit  in  the  second  set;  and  place  the  divisor  in  the  first.  Would  it  not  be  enough  to 
say  transpose  the  fruits  of  both  sets  ?  The  author  of  the  Caumudi  replies  "  the  designation  of 
divisor  serves  to  indicate,  that,  after  transposition,  the  fruit  of  the  second  set,  being  included  in  the 
product  of  the  multiplication  of  the  less  set  of  terms,  the  product  of  the  greater  set  is  to  be  divided 
by  it."  '  Some,  however,  interpret  it  as  relative  to  fractions  ["  transpose  denominators,  if  any 
there  be." — Gavg.]     But  that  is  wrong:  for  the  word  would  be  superfluous.' 

♦  Ba/tu-rdsi  (pacsha),  set  of  many  terms  :  the  one  which  is  most  numerous.  (That,  to  which  the 
fruit  is  brought,  is  the  larger  set. — Gang,  Or,  if  there  be  fruit  on  both  sides,  that,  in  which  the 
fruit  of  the  requisition  is, — Gan.)    Laghu-rdsi,  set  of  fewer  terms ;  that,  which  is  less  numerous. 

?3 


36  Ll'LAVATI'.  Chapter  III- 

80.  Example.  If  the  interest  of  a  hundred  for  a  month  he  five,  say  what 
is  the  interest  of  sixteen  for  a  year?  Find  likewise  the  time  from  the 
principal  and  interest;  and  knowing  the  time  and  produce,  tell  the  principal 
sum. 

1      12 
Statement:  100  \6     'Answer:  the  interest  is  9f. 

5  1 

To  find  the  time ;   Statement:   100    16     *  Answer:   months  12. 

K  4  8 

■^  i" 

To  find  the  principal ;  Statement:   1      12     'Answer:  principal  16. 

100 

81.  Example.  If  the  interest  of  a  hundred  for  a  month  and  one-third, 
be  five  and  one  fifth,  say  what  is  the  interest  of  sixty-two  and  a  half  foJ' 
three  months  and  one  fifth  ? 

A         l_6 

3  i 

Statement:   'f"  >f*      ♦Answer:  interest  7|^. 
V 


„  .       ,    ,    ..    L  ^1     Product  of  the  larger  set,  960     Quotient,  960  ^,  48 

^Transpos»>gthefru.t,100l|  of  the  less  set,      100.  ToO  ""^  T. 

1  1 

*  Transposing  both  fruits,     ^     ^  and  the  denominator,    ^g     ^ 

5 
Product  of  the  larger  set,  4800 

of  the  less  set,        400.     Quotient,  12. 

1  12                                                1     12 

'  Transposing  both  fruits,  100  and   the    denominator,   100 

V  5                                                  48     5 

^  5 
Product  of  the  larger  set  4800 

of  the  less  set  300.     Quotient,  16. 

«  Transposing  the  fruit,  4     V*  and  the  denominators,    *      '36  Abridging  by  correspondent  re- 


100    Its 


00   1|4  »J"     »» 

auction  on  both  sides*   1     4,  and  by  further  reduction,   1      1     Answer  V  <»«"  7f 

5     3  13 

4  5  11 
2     1  11 

5  26  5  13 

•  The  Man<!ron/«na  teaches  to  abridge  the  work  by  reduction  of  terun  on  both  sides  by  their  common  diTiJors. 


Section  VI. 


RULE  OF  PROPORTION. 


37 


82.  Example  of  the  rule  of  seven:  If  eight,  best,  variegated,  silk  scarfs, 
measuring  three  cubits  in  breadth  and  eight  in  length,  cost  a  hundred 
[nisficasl ;  say  quickly,  merchant,  if  thou  understand  trade,  what  a  like  scarf, 
three  and  a  half  cubits  long  and  half  a  cubit  wide,  will  cost. 


Statement:  8  -|- 

8   1 
100 


'Answer:  Nishca  0,  drammas   14,  panas  9,  cdcini   1, 
cowry  shells  6f . 


83.  Example  of  the  rule  of  nine :  If  thirty  benches,  twelve  fingers 
thick,  square  of  four  wide,  and  fourteen  cubits  long,  cost  a  hundred  [nishcas]; 
tell  me,  my  friend,  what  price  will  fourteen  benches  fetch,  which  are  four 
less  in  every  dimension  ? 


Statement: 

;  12 

8 

16 

12 

14 

10 

30 

14 

100 

*  Answer:  Nishcas  \6\. 


84.  Example  of  the  rule  of  eleven :  If  the  hire  of  carts  to  convey 
the  benches  of  the  dimensions  first  specified,  a  distance  of  one  league 
(gavyuti,y  be  eight  drammas;  say  what  should  be  the  cart-hire  for  bringing 
the  benches  last  mentioned,  four  less  in  every  dimension,  a  distance  of  six 
leagues  r 


•  Transposing  fruit  and  denominators,  3 

2 


•  Transposing  fruit,  1 2 
16 
14 
30 


8     7 
2 

8     1 
100 

8     abridi»ing  by 

12  correspondent 

10    reduction  on 

14      both  sides; 

100 


1     Product  oflarger  set,  700      Quotient,  0  14  9  1  6| 
of  less  set,     768. 


1 
I 
I 
1 

100 


Product  of  larger  set,  100      Quotient,  l6| 
of  <e«  set,       6    . 


'   Gary^ifi ;  two  cr6sas  or  \ia\( a  yojana  :  if  contains  4000  rfoHf/rt,?  or  fathoms;  about  8000  yards; 
and  is  about  3,  8  B.  miles  :  the  crosa  being  1,  9  B.  m.     See  As.  Res.  5.  Wo. 


IS 

8 

16 

12 

Statement : 

14 

10 

30 

14 

1 

6 

8 

58  LI'LA'VATI.  Chapter  III. 


'Answer :  Drammas  8. 


85.  Rule  of  barter;*  half  a  stanza.  ^^^ 

So  in  barter  likewise,  the  same  process  is  [followed;]  transposing  both 
prices,  as  well  as  the  divisors.' 

86.  Example.  If  three  hundred  mangoes  be  had  in  this  market  for  one 
dramma,  and  thirty  ripe  pomegranates  for  a  pana,  say  quickly,  friend,  how 
many  should  be  had  in  exchange  for  ten  mangoes  ? 

Statement:  16     1     *Answer:   16  pomegranates. 
300  30 
10 

*  Transposing  the  fruit,  12     8    abridging  by  1     1  and  by  further  1     I 

\6  12  correspondent  2  1  reduction,      1     1 

14  10  reduction  on  1  1  11 

30  14      both  sides,    3  1  11 

1     6                          1  6  12 

8  8  4 

Product  of  larger  set,  8     ^      .     ,  „ 
,,    ^         '  ,     Quotient, 8. 
of  less  set,      1 

•  BMnda-prati-bkdndaca  commodity   for  commodity ;  computation  of  the  exchange  of  goods 
{XKUtu-vinimayO'ganita, — Gang.)  :   barter. 

»  Gakgad'hara,  Su'ryada'sa  and  the  Manoranjana  so  read  this  passage:   hardns-cha  maulye. 

But  Gan'e'sa  and  Ranganat'ha  have  the  affirmative  adverb  sadA-hi,  in  place  of  the  words  "  and 

the  divisors ;"  har&ns-cha.     At  all  events,  the  transposition  of  denominators  takes  place,  as  usual ; 

and  so  does  that  of  the  lower  term,  as  in  the  rule  of  five  ;   to  which,  as  Su'ryada'sa  remarks,  this 

is  analogous.    It  comprises  two  proportions,   thus  stated   by  him  from  the  example  in  the  text. 

"   If  for  one  paiia,  thirty  pomegranates  may  be  had,  how  many  for  sixteen?     Answer,   480. 

Again,  if  for  three  hundred   mangoes,  four  hundred  and  eighty  pomegranates  maybe  had,  how 

many  for  ten  ?     Answer,  l6.    Here  thirty  is  first  multiplied  by  sixteen  and  then  divided  by  one  ; 

and  then  multiplied  by  ten  and  divided  by  three  hundred.    For  brevity,  the  prices  are  transposed, 

and  the  result  is  the  same."  Su'r. 

■♦  Transposing  the    prices,     1       \G    and,    transferring  the  fruit,     1       \6     Then    product 

300     30  300     30 

10  10 

of  the  larger  set,  4800    Quotient,  l6.    Or,  by  correspondent  reduction,     1  1 6  and  further  1  l6 

of  the  less  set,        300.  10     1  11 

10  1 

Whence  products  i6  and  quotient  \Q. 
1 


I 


(     39     ) 


CHAPTER  IV. 


INVESTIGATION  OF  MIXTURE. 


SECTION  I. 

INTEREST. 

87 — 88.     Rule  :  a  stanza  and  a  half.' 

The  argument'  multiphed  by  its  time,  and  the  fruit  multiplied  by  the  mixt 
quantity's  time,  being  severally  set  down,  and  divided  by  their  sum  and 
multiplied  by  the  mixt  quantity,  are  the  principal  and  interest  [composing 
the  quantity].  Or  the  principal  being  found  by  the  rule  of  supposition,  that, 
taken  from  the  mixt  quantity,  leaves  the  amount  of  interest. 


89.  Example.  If  the  principal  sum,  with  interest  at  the  rate  of  five  on 
the  hundred  by  the  month,  amount  in  a  year  to  one  thousand,  tell  the 
principal  and  interest  respectively. 

1        12 
Statement:   100  1000.     ^Answer:  Principal,  625;  Interest,  375. 
5 

Or,  by  the  rule  of  position,  put  one ;  and  proceeding  according  to  that 
rule  (§  50),  the  interest  of  unity  is  f;  which,  added  to  one,  makes  f.     The 

'  it/wrn-rj/araAiira,  investigation  of  mixture,  ascertainment  of  composition,  as  principal  and  interest 
joinei),  and  so  forth. — Gajj.  It  is  chiefly  grounded  on  the  rule  of  proportion. — Ibid.  The  rules  in 
this  chapter  bear  reference  to  the  examples  which  follow  them.  Generally  they  are  quasstiones 
otiosae  ;  problems  for  exercise. 

^  *  To  investigate  a  mixt  amount  of  principal  and  interest. — Gas.  The  first  rule  agrees  with 
Srid'hara's  {Gari.  sdr.  §  91).  The  second  answers  to  one  deduced  from  BRAiiMEGurxA  by  his 
Commentator.     Arithm.  of  Braiim.  §  14. 

*  Pramiiia  argument ;  and  phala  fruit  {S  70):  principal  and    interest. 

♦  100  multiplied  by  1  is  100  ;  5  by  12  is  60.  Their  sum  l60  is  the  divisor.  The  first  number, 
100,  multiplied  by  1000,  and  divided  by  l60,  is  625.  The  second  60,  multiplied  by  1000  and 
divided  by  l60,  gives    375.  Gang. 


40  LI'LA'VATI'.  Chapter  IV. 

given  quantity  1000,  multiplied  by  unity,  and  divided  by  that,  shows  the 
principal  625.     This,  taken  from  the  mixt  amount,  leaves  the  interest  375. » 

90.  Rule:'  The  arguments  taken  into  their  respective  times  are  divided 
by  the  fruit  taken  into  the  elapsed  times;  the  several  quotients,  divided  by 
their  sum  and  multiplied  by  the  mixt  quantity,  are  the  parts  as  severally 
lent. 

91.  Example :  The  sum  of  six  less  than  a  hundred  nishcas  being  lent  in 
three  portions  at  interest  of  five,  three  and  four  per  cent,  an  equal  interest 
was  obtained  on  all  three  portions,  in  seven,  ten,  and  five  months  respectively^ 
Tell,  mathematician,  the  amount  of  each  portion.' 

Statement:     17  1     10  15     Mixt  amount  94.* 

100  100  100 

5  3  4 

Answer :  the  portions  are  24,  28  and  42.   The  equal  amount  of  interest  8f . 

92.  Rule:  half  a  stanza.' 

*  Or  the  principal  being  known,  the  interest  may  be  found  by  the  role  of  five.  Su'r. 
-  For  determining  parts  of  a  compound  sura.  Sun. 

»  Since  the  amount  of  interest  on  all  the  portions  is  the  same,  put  unity  for  its  arbitrarily  assumed 
amount :  whence  corresponding  principal  sums  are  found  by  the  rule  of  five.  For  instance,  if  a 
hundred  be  the  capital,  of  which  five  is  the  interest  for  a  month,  what  is  the  capital  of  which  unity 
is  the  interest  for  seven  months  ?  and,  in  like  manner,  the  other  principal  suras  are  to  be  found. 
Thus,  a  compound  proportion  being  wrought,  the  time  is  multiplied  by  the  argument  to  which  it 
appertains,  and  divided  by  the  fruit  taken  into  the  elapsed  time.  Then,  as  the  total  of  those 
principal  suras  is  to  them  severally,  so  is  the  given  total  to  the  respective  portions  lent.  They  are 
thus  severally  found  by  the  rule  of  three.  Gan. 

♦  Multiplying  the  argument  and  fruit  by  the  times,  and  dividing  one  product  by  the  other,  there 

result   the  fractions  y^    Jj"^"    J^  or  «^  «/  SJ*;  which    reduced  to  a  coramon  denominator   and 

summed,  make  i^f  or  '^;  multiplied  by  the  mixt  amount  94,  they  are  '^",  '*/",  '^°;  and 

then  divided  by  the  sum  ^^,  they  give  >^8,  ifs,  «|8,  or  24.,  28,  42.  Mono. 

1      7 
To  find  the  interest,  employ  the  rule  of  five  ;  100  24.     Answer,  8f .     By  the  same  method,  witk  ■ 

5 
all  three  portions,  the  interest  comes  out  the  same.  Su'r. 

^  The  capital  sums,  their  aggregate  amount,  and  the  sum  of  the  gains  being  given  ;  to  apportion 

the  gains. — Gan.  The  rule  is  taken  from  Braumegupta,  Arithm.  §  l6.  It  answers  to  Sijid'uara  s, 

Gan.  sdr.  §  109. 


Sect.  I.  MIXTURE.  41 

The  contributions,'  being  multiplied  by  the  mixt  amount  and  divided  by 
the  sum  of  the  contributions,  are  the  respective  fruits.'* 

93.  Example.  Say,  mathematician,  what  are  the  apportioned  shares  of 
three  traders,  whose  original  capitals  were  respectively  fifty-one,  sixty-eight, 
and  eighty-five ;  which  have  been  raised  by  commerce  conducted  by  them 
on  joint  stock,  to  the  aggregate  amount  of  three  hundred? 

Statement:  51,68,85.     Sum:  204.     Mixt  amount :  300. 

Answer:  75,  100,  125.  These,  less  the  capital  sums,  are  the  gains:  viz. 
24,   32,  40. 

Or  the  mixt  amount,  less  the  sum  of  aggregate  capital,  is  the  profit  on 
the  whole :  viz.  96.  This  being  multiplied  by  the  contributions,  and 
divided  by  the  sum  of  the  contributions,  gives  the  respective  gains ;  viz. 
24,  32,  and  40. 


*  Pracshepaca,  that  which  is  thrown  in  or  mixt. — Gan.     Joined  together. — Sua. 

^  The  principle  of  the  rule  is  obvious,  being  simply  the  rule  of  three.— Gan.  '  If  by  this  sum 
of  contributions,  this  contribution  be  had,  then  by  the  compound  sum  what  will  be  ?  The  numbers 
thus  found,  less  the  contributions,  are  the  gains.'  Vhand  by  Rang. 


(    42     ) 

SECTION  II. 

FRACTIONS. 

94.  Rule  :•  half  a  stanza. 

Divide  denominators  by  numerators  ;  and  then  divide  unity  by  those  quo- 
tients added  together.  The  result  will  be  the  time  of  filling  [a  cistern  by 
several  fountains.]* 

95.  Example.  Say  quickly,  friend,  in  what  portion  of  a  day  will  [four] 
fountains,  being  let  loose  together,  fill  a  cistern,  which,  if  severally  opened, 
they  would  fill  in  one  day,  half  a  day,  the  third,  and  the  sixth  part,  respec- 
tively ? 

Statement:  yiii. 

Answer :   ^th  part  of  a  day. 


'  To  apportion  the  time  for  a  mixture  of  springs  to  fill  a  well  or  cistern. — Gan.  To  solve  an 
instance  relative  to  fractions. — Su'r.  A  similar  problem  occurs  in  Bbahmegupta's  Arithmetic, 
§8. 

*  The  rule  is  grounded  on  a  double  proportion,  according  to  Gan'es'a  and  RanganaVha  j 
but  on  the  rule  of  three  inverse,  according  to  Su'ryada'sa  and  the  Manoranjana:  "  if  by  one 
fountain's  time  one  day  be  bad  ;  then,  by  all  the  fountains'  times  in  portions  of  days,  summed  to- 
gether, what  is  had  f"  Or,  "  If,  by  this  portion  of  a  day  one  cistern  be  filled,  how  many  by  a 
whole  day  ?"  Then,  after  adding  together  the  number  of  full  cisterns,  "  if,  by  so  many,  one  day 
be  had,  then  by  one  cistern  what  will  be?* 


(     43     )  W^ 


SECTION  III. 

PURCHASE  and  SALE. 

96.  Rule.'  By  the  [measure  of  the]  commodities,*  divide  their  prices 
taken  into  their  respective  portions  [of  the  purchase] ;  and  by  the  sum  of 
the  quotients  divide  both  them  and  those  portions  severally  multiplied  by 
the  mixt  sum  :  the  prices  and  quantities  are  found  in  their  order.' 

97.  Example  :*  If  three  and  a  half  manas^  of  rice  may  be  had  for  one 
dramma,  and  eight  of  kidney-beans*  for  the  like  price,  take  these  thirteen 
cdcitiis,  merchant,  and  give  me  quickly  two  parts  of  rice  with  one  of  kidney- 
beans  ;  for  we  must  make  a  hasty  meal  and  depart,  since  my  companion 
will  proceed  onwards. 

Statement :    f  -f     Mixt  sum  J^. 


1  1 
±   ». 

2  1 


1  For  a  case  where  a  mixture  of  portions,  and  composition  of  tilings,  are  given. — Gan.  Con- 
cerning measure  of  grain,  &c. — Su'r.     See  Srid'hara,  §  II6. 

-  Panija:  the  measure  of  the  grain  or  other  commodity  procurable  for  the  current  price  in 
the  market.  Su'r.  and  Mano. 

*  Founded  on  the  rule  of  proportion  :  *  if  by  this  measure  of  goods  this  price  be  obtained,  then 
by  this  portion  of  goods  what  will  be  ?'  So  for  the  second  commodity.  Then,  summing  the  prices 
so  found,  '  if  by  this  sum,  these  several  prices,  then  by  this  mixt  amount  what  prices  f  and,  *  if 
by  this  sum,  these  portions,  then  by  this  mixt  amount  what  quantities?'  Rang. 

■*  See  Vija-gaiiita,  §  115;  which  is  word  for  word  the  same. 

•  M&na  or  Mdnaca  a  measure;  seemingly  intending  a  particular  one;  the  same  with  the 
mddicd,  according  to  the  Manoranjana,  if  a  passage  in  the  margin  of  that  commentary  be  genuine. 
The  M/tnicd  is  the  quarter  of  the  c'/uiri.  See  Ciiaturveda  on  Braiimegupta,  §  11.  But,  ac- 
cording to  Gan'es'a,  the  mada  (apparently  the  same  with  the  mMic6)  is  at  most  an  eighth  of  a 
c'Mri;  being  a  cubic  span.  See  note  to  §236.  A  spurious  couplet  (see  note  on  §  2.)  makes  it 
the  modern  measure  of  weight  containing  forty  shs. 

6   Mu'dga:  Phaseolus  mungo;  sort  of  kidney-bean, 

OS 


44  LI'LAVATI'.  Chapter  IV. 

The  prices,  ■}■  \,  multiplied  by  the  portions  f  |,  and  divided  by  the  goods 
i  A,  make  a  x;  the  sum  of  which  is  f^.  By  this  divide  the  same  fractions 
(±  i)  taken  into  the  mixt  sum  (xj.) ;  and  the  portions  (|  i)  taken  into  that 
mixt  sum  (^).  There  result  the  prices  of  the  rice  and  kidney-beans,  f 
and  -^  of  a  dramma;  or  10  cdcinis  and  13-l  shells  for  the  rice,  and  2  cdcinis 
and  6|-  shells  for  the  kidney-beans  ;  and  the  quantities  are  -^  and  -^Jy  of  a 
m</;2a  of  rice  and  kidney -beans  respectively. 

98.  Example.  If  a  pala  of  best  camphor  may  be  had  for  two  nishcas, 
and  a  pala  of  sandal-wood'  for  the  eighth  part  of  a  dramma,  and  half  a  pala 
of  aloe-wood  *  also  for  the  eighth  of  a  dramma,  good  merchant,  give  me 
tlie  value  of  one  nishca  in  the  proportions  of  one,  sixteen  and  eight :  for  I 
wish  to  prepare  a  perfume. 

Statement :  32     ^    -|^        Mixt  sum  16. 

1      1     i 

1    16     8 
Answer:    Prices:  drammas     14-|  -f  f. 
Quantities:  palas     ■*    V  V* 


1   Chandana:  Santalum  album. 
■  Aguru:  Aquillaria  Agallochum. 


» 


(     45     ) 


SECTION  IV. 

99-     Rule.     Problem  concerning  a  present  of  gems.^ 

From  the  gems  subtract  the  gift  multiplied  by  the  persons ;  and  any  ar- 
bitrary number  being  divided  by  the  remainders,  the  quotients  are  numbers 
expressive  of  the  prices.  Or  the  remainders  being  multiplied  together,  the 
product,  divided  by  the  several  reserved  remainders,  gives  the  values  in 
whole  numbers.  " 

100.  Example.  Four  jewellers,  possessing  respectively  eight  rubies,  ten 
sapphires,  a  hundred  pearls,  and  five  diamonds,  presented,  each  from  his  own 
stock,  one  apiece  to  the  rest  in  token  of  regard  and  gratification  at  meeting : 
and  they  thus  become  owners  of  stock  of  precisely  equal  value.  Tell  me, 
severally,  friend,  what  were  the  prices  of  their  gems  respectively  ? 

Statement:  Rub.  8;  sapph.  10;  pearls  100;  diam.  5.    Gift  1.     Persons4. 

Here,  the  product  of  the  gift  1  by  the  persons  4,  viz.  4,  being  severally 
subtracted,  there  remain  rubies  4;  sapphires  6  ;  pearls  96;  diamond  1.  Any 
number  arbitrarily  assumed  being  divided  by  these  remainders,  the  quotients 
are  the  relative  values.  Taking  it  at  random,  they  may  be  fractional  values; 
or  by  judicious  selection,  whole  numbers:  thus,  put  96;  and  the  prices 
thence  deduced  are  24,  I6,  1,  96 ;  and  the  equal  stock  233. 

Or  the  remainders  being  multiplied  together,  and  the  product  severally  di- 
vided by  those  remainders,  the  prices  are  576,  384,  24,  2304  :  and  the  equal 
amount  of  stock  (after  interchange  of  presents)  is  5592' 


»  The  problem  is  an  indeterminate  one.     The  solution  gives  relative  values  only. 

*  Su'ryada'sa  cites  the  V'lja-gaiiita  for  the  solution  of  the  problem.  (See  Vija-gati.^  11.  where 
the  same  example  occurs.)  The  principle  is  explained  by  RanganaVha  without  reference  to 
algebra.  It  is  founded  on  the  axiom,  that  "  equality  continues,  if  addition  or  subtraction  of 
equal  things  be  made  to  or  from  equal  things."  After  interchange  of  presents,  each  person  has 
one  of  every  sort  of  gem,  and  a  certain  further  number  of  one  sort.  Deducting  then  one  of  each 
sort  from  the  equalized  stock  of  every  person,  remains  a  number  of  a  single  sort  equal  in  value  one 
to  the  other.  Put  an  arbitrary  number  for  that  value ;  and  make  the  proportion  ;  '  as  this  number 
of  gems  is  to  this  equal  value,  so  is  one  gem  to  its  price.'  Rang. 


(    46    ) 

SECTION  V. 

ALLIGATION}       * 

101.  ,  Rule.s  The  sum  of  the  products  of  the  touch'  and  [weight  of  se- 
veral parcels]*  of  gold  being  divided  by  the  aggregate  of  the  gold,  the  touch 
of  the  mass  is  found.  Or  [after  refining]  being  divided  by  the  fine  gold,  the 
touch  is  ascertained ;  or  divided  by  the  touch,  the  quantity  of  purified  gold 
is  determined.' 

J02 — 103.  Example.  Parcels  of  gold  weighing  severally  ten,  four,  two 
and  four  mdshas,  and  of  the  fineness  of  thirteen,  twelve,  eleven  and  ten  respec- 
tively, being  melted  together,  tell  me  quickly,  merchant,  who  art  conver- 
sant with  the  computation  of  gold,  what  is  the  fineness  of  the  mass  ?  If  the 
twenty  mdshas  above  described  be  reduced  to  sixteen  by  refining,  tell  me 
instantly  the  touch  of  the  purified  mass.  Or,  if  its  purity  when  refined  be 
sixteen,  prithee  what  is  the  number  to  which  the  twenty  mashas  are  re- 
duced ? 

Statement:  Touch    13     12     11     10. 

Weight   10       4       2       4. 

Answer:*  After  melting,  fineness   12. 

Weight  20. 

1  Suverda-gariita  ;  computation  of  gold  ;  that  is,  of  its  weight  and  fineness.  Alligation  medial. 
Sri'd'iiara  has  similar  rules,  ^S9 — 108.  The  topic  is  unnoticed  by  Braumegupta  ;  but  the 
omission  is  supplied  by  his  commentator.  See  Chaturve'da  on  Brahmegupta's  Arithm.  note 
to  Sect.  2. 

-  To  find  the  fineness  produced  by  mixture  of  parcels  of  gold;  and,  after  refining,  the  weight, 
if  the  fineness  be  known  ;  and  the  fineness,  if  the  weight  of  refined  gold  be  given.  Gan. 

3  Varna,  colour  of  gold  on  the  touchstone.  Fineness  of  gold  determined  by  that  touch.  See 
§  77.     "  The  degrees  of  fineness  increase  as  the  weight  is  reduced  by  refining." — Gan. 

*  Gang. 

*  The  solution  of  the  problem  is  grounded  on  the  rule  of  supposition,  together  with  the  rule  of 
three  inverse  :  as  shown  at  large  by  Uangan  a't'ha  and  Gan'e's'a  under  this  and  §  77. 

6  Products  130,  48,  22,  40.     Their  sura  240;  divided  by  20,  gives  12:  divided  by  iff,  gives  15. 


Sect.  V.  ALLIGATION.  47, 

After  refilling,  the  weight  being  sixteen  wzfl*//a5 ;  touch  15.  The  touch 
being  sixteen ;  weight  15. 

104.  Rule."  From  the  acquired  fineness  of  the  mixture,  taken  into  the 
aggregate  quantity  of  gold,  subtract  the  sum  of  the  products  of  the  weight 
and  fineness  [of  the  parcels,  the  touch  of  which  is  known,]  and  divide  the 
remainder  by  the  quantity  of  gold  of  unknown  fineness;  the  quotient  is  the 
degree  of  its  touch.' 

105.  Example.  Eight /was/m*  of  ten,  and  two  of  eleven  by  the  touch, 
and  six  of  unknown  fineness,  being  mixed  together,  the  mass  of  gold,  my 
friend,  became  of  the  fineness  of  twelve ;  tell  the  degree  of  unknown  fine- 
ness. 

Statement:   10     11  Fineness  of  the 

8       2     6  mixture  12. 

Answer:  Degree  of  the  unknown  fineness  15, 

106.  Rule,'  The  acquired  fineness  of  the  mixture  being  multiplied  by 
the  sum  of  the  gold  [in  the  known  parcels],  subtract  therefrom  the  aggre- 
gate products  of  the  weight  and  fineness  [of  the  parcels]  :  divide  the  re- 
mainder by  the  difference  between  the  fineness  of  the  gold  of  unknown 
weight  and  that  of  the  mass,  the  quotient  is  the  weight  of  gold  that  was 
unknown. 

107-  Example.  Three  mdshas  of  gold  of  the  touch  often,  and  one  of 
the  fineness  of  fourteen,  being  mixt  with  some  gold  of  the  fineness  of  six- 
teen, the  degree  of  purity  of  the  mixture,  my  friend,  is  twelve.  How  many 
mdshas  were  there  of  the  fineness  of  sixteen  ? 

Statement:  10     14     16  Fineness  of  the 

3       1  mixture  12. 

Answer :  Mdsha  1 . 

*  To  discover  the  fineness  of  a  parcel  of  unknown  degree  of  purity  mixed  with  others  of  which 
the  touch  was  known.  Gait. 

'  The  rule  being  the  converse  of  the  preceding,  the  principle  of  it  is  obvious.  Rang. 

3  To  find  the  weight  of  a  parcel  of  known  fineness,  but  unknown  weights,  raixt  with  other  parcels 
of  known  weight  and  fineness.  Gan. 


48  LI'LA'VATr.  Chapter  IV. 

108.  Rule.*  Subtract  the  effected  fineness  from  that  of  the  gold  of  a 
higher  degree  of  touch,  and  that  of  the  one  of  lower  touch  from  the  effected 
fineness;  the  differences,  multiplied  by  an  arbitrarily  assumed  number,  will 
be  the  weight  of  gold  of  the  lower  and  higher  degrees  of  purity  respectively.  * 

109.  Example.  Two  ingots  of  gold,  of  the  touch  of  sixteen  and  ten 
respectively,  being  mixt  together,  the  gold  became  of  the  fineness  of  twelve  : 
tell  me,  friend,  the  weight  of  gold  in  both  lumps. 

Statement:  16,  10.     Fineness  resulting  12. 

Putting  one,  and  multiplying  by  that ;  and  proceeding  as  directed ;  the 
weights  of  gold  are  found,  mdshas  2  and  4.  Assuming  two,  they  are  4  and 
8.  Taking  half,  they  come  out  1  and  2.  Thus,  manifold  answers  are  ob- 
tained by  varying  the  assumption. 

'  To  find  the  weight  of  two  parcels  of  given  fineness  and  unknown  weight. — Gan.  and  Sue. 
A  rule  of  alligation  alternate  in  the  simplest  case.  The  problem  is  an  indeterminate  one  :  as  is  in* 
timated  by  the  author. 

2  By  as  much  as  the  higher  degree  of  fineness  exceeds  the  fineness  effected,  so  much  is  the 
measure  of  the  weight  of  less  pure  gold ;  and  by  as  much  as  the  lower  degree  of  purity  is  under  the 
standard  of  the  mixture,  so  much  is  the  weight  of  the  purer  gold.  Sur. 


(     49     )  ^''■ 

SECTION    VI. 

PERMUTATION  and  COMBINATION. 

110 — 112.     Rule:'  three  stanzas. 

Let  the  figures  from  one  upwards,  differing  by  one,  put  in  the  inverse 
order,  be  divided  by  the  same  [arithmeticals]  in  the  direct  order ;  and  let  the 
subsequent  be  multiplied  by  the  preceding,  and  the  next  following  by  the 
foregoing  [result].  The  several  results  are  the  changes,  ones,  twos,  threes, 
&c.*  This  is  termed  a  general  rule.'  It  serves  in  prosody,  for  those  versed 
therein,  to  find  the  variations  of  metre ;  in  the  arts  [as  in  architecture]  to 
compute  the  changes  upon  apertures  [of  a  building] ;  and  [in  music]  the 
scheme  of  musical  permutations;*  in  medicine,  the  combinations  of  different 
savours.     For  fear  of  prolixity,  this  is  not  [fully]  set  forth. 

113.  A  single  example  in  prosody:  In  the  permutations  of  the  g&yatri 
metre,'  say  quickly,  friend,  how  many  are  the  possible  changes  of  the  verse? 
and  tell  severally,  how  many  are  the  combinations  with  one,  [two,  three,]  &c. 
long  syllables .'' 

Here  the  verse  of  the  gciyatri  stanza  comprises  six  syllables.     Wherefore, 

'  To  find  the  possible  permutations  of  long  and  short  syllables  in  prosody ;  combinations  of 
ingredients  in  pharmacy  ;  variations  of  notes,  &c.  in  music;  as  well  as  changes  in  other  instances. 

Gan. 

*  According  to  Gan'e's'a,  there  is  no  demonstration  of  the  rule,  besides  acceptation  and  ex- 
perience. Rangana't'ha  delivers  an  explanation  of  the  principle  of  it  grounded  on  the  summing 
of  progressions. 

'  Commentators  appear  to  interpret  this  as  a  name  of  the  rule  here  taught ;  s/icTMrana,  or 
gid'hdranorch'handu-gaiiila,  general  rule  of  prosodian  permutation  :  subject  to  modification  in 
particular  instances ;    as   in  music,  where  a  special  method   (as6d'h6ram)  must  be  applied. 

Gang.  Sub. 

♦  Chanda-meru :  acertain  scheme. — Gan.  It  is  more  fully  explained  by  other  commentators:  but 
the  translator  is  not  sufficiently  conversant  with  the  theory  of  music  to  understand  the  term  distinctly. 

'  The  GAyatri  metre  in  sacred  prosody  is  a  triplet  comprising  twenty-four  syllables  :  as  in  the 
famous  prayer  containing  the  Brahmenical  creed,  called  gAyatri,  (See  As.  Res.  vol.  10,  p.  463). 
But,  in  the  prosody  of  profane  poetry,  the  same  number  of  syllables  is  distributed  in  a  tetrastic  : 
and  the  verse  consequently  contains  six  syllables.   (As.  Res.  vol.  10,  p.  469.) 

H 


I 


50  LI'LAVATI'.  Chapter  IV. 

the  figures  from  one  to  six  are  set  down,  and  the  statement  of  them,  in 
direct  and  inverse  order  is  ?  |  J  J  |J.  Proceeding  as  directed,  the  results  are, 
changes  with  one  long  syllable,  6";  with  two,  15  ;  with  three,  20 ;  with  four, 
15;  with  five,  6;  with  six,  1;  with  all  short,  1.  The  sum  of  these  is  the 
whole  number  of  permutations  of  the  verse,  64. 

In  like  manner,  setting  down  the  numbers  of  the  whole  tetrastic,  in  the 
mode  directed,  and  finding  the  changes  with  one,  two,  &c.  and  summing 
them,  the  permutations  of  the  entire  stanza  are  found:   16777216. 

In  the  same  way  may  be  found  the  permutations  of  all  varieties  of  metre, 
from  Uctd  [which  consists  of  monosyllabic  verses]  to  Utcfiti  [the  verses  of 
which  contain  twenty-six  syllables.]' 

1 14.  Example :  In  a  pleasant,  spacious  and  elegant  edifice,  with  eight 
doors,*  constructed  by  a  skilful  architect,  as  a  palace  for  the  lord  of  the  laud, 
tell  me  the  permutations  of  apertures  taken  one,  two,  three,  &c.'  Say,  mathe- 
matician, how  many  are  the  combinations  in  one  composition,  with  ingredients 
of  six  different  tastes,  sweet,  pungent,  astringent,  sour,  salt  and  bitter,* 
taking  them  by  ones,  twos,  or  threes,  &c. 


Statement  [1st  Example]: 


ST6543el 
1234S6TS' 


Answer :  the  number  of  ways  in  which  the  doors  may  be  opened  by  ones, 
twos,  or  threes,  &c.  is  8,  28,  56,  70,  56,  28,  8,  1.     And  the  changes  on  the 

IS  34  56T8 

apertures  of  the  octagon  *  palace  amount  to  255. 


Statement  2d  example  :  *  5  J  4  j  J- 

Answer :  the  number  of  various  preparations  with  ingredients  of  divers 
tastes  is 6,  15,  20,  15,  6,  l.f 

12  3  4  5      6 

*  A«iat.  Res.  vol.  10,  p.  468—473. 

*  Mdc'hi,  aperture  for  the  admission  of  air  :  a  door  or  window  ;  (same  with  gax&csha  ; — Gan'.) 
a  portico  or  terrace,  {hhumi-visesha  ; — Gang,  and  Su'r.) 

^  The  variations  of  one  window  or  portico  open  (or  terrace  unroofed)  and  the  rest  closed ;  two 
open,  and  the  rest  shut ;  and  so  forth, 

*  Amera-cosha  1.3.  18. 

*  An  octagon  building,  with  eight  doors  (or  windows;  porticos  or  terraces;)  facing  the  eight 
cardinal  points  of  the  horizon,  is  meant.     See  Gan. 

+  Total  number  of  possible  combinations,  63.    Gang. 


(     51     ) 


I 


CHAPTER  V. 

PROGRESSIONS.' 


SECTION  I. 

ARITHMETICAL    PROGRESSION. 

115.  Rule  :"  Half  the  period,'  multiplied  by  the  period  added  to  unity, 
is  the  sum  of  the  arithmeticals  one,  &c.  and  is  named  their  addition.*  This! 
being  multiplied  by  the  period  added  to  two,  and  being  divided  by  three,  is 
the  aggregate  of  the  additions.' 

•  Src-d-hi,  a  term  employed  by  the  older  authors  for  any  set  of  distinct  substances  or  other  things 
put  together.-GAN.  It  signifies  sequence  or  progression.  Sred'hUyavahdra,  ascertainment  or 
determination  of  progressions. 

'  To  find  the  suras  of  the  arithmeticals.— Gan. 

^  Pada  the  place.-GAN.  Any  one  of  the  figures,  or  digits ;  being  that  of  which  the  sum  is  re- 
quired.—Sub.     The  last  of  the  numbers  to  be  »ummed.-i»fa«6.     See  below  :  note  to  §  1 19. 

♦  Sancaht6,  the  first  sum,  or  addition  of  arithmeticals.  5ancattaicj,a,  aggregate  of  additions, 
summed  sums,  or  second  sum. 

»  The  first  figure  is  unity.  The  sum  of  that  and  the  period  being  halved,  is  the  middle  figure. 
As  the  figures  decrease  behind  it,  so  they  increase  before  it:  wherefore  the  middle  figure,  multi- 
plied by  the  period,  .s  the  sum  of  the  figures  one,  &c.  continued  to  the  period.  The  only  proof  of 
the  rule  for  the  aggregate  of  sums,  is  acceptation.-GAN.  It  is  a  maxim,  that  '  a  number  multi- 
pl.edby  the  next  following  arithmetical,  and  halved,  gives  the  sum  of  the  preceding:'  wherefore, 
&c.  Sua.  Camalacara  is  quoted  by  Ranganat'ha  for  a  demonstration  grounded  on  placing 
the  numbers  of  the  progression  in  the  reversed  order  under  the  direct  one:  where  it  becomes 
obvious,  that  each  pair  of  terms  gives  the  like  sum  :  wherefore  this  sum,  multiplied  by  the  number 
of  terms,  is  twice  the  sura  of  the  progression. 

h2 


52  LI'LA'VATI'.  Chapter  V. 

116.  Example:  Tell  me,  quickly,  mathematician,  the  sums  of  the 
several  [progressions  of]  numbers  one,  &c.  continued  to  nine;  and  the  sum- 
med sums  of  those  numbers. 

Statement:     Arithmeticals :  12345678       9. 
Answer:         Sums:  1     3     6     10  15  21  28  36     45. 

Summed  sums:  1     4     10  20  35  56  84  120  165. 

1 17.  Rule :'  Twice  the  period  added  to  one  and  divided  by  three,  being 
multiplied  by  the  sum  [of  the  arithmeticals],  is  the  sum  of  the  squares. 
The  sum  of  the  cubes  of  the  numbers  one,  &c.  is  pronounced  by  the  ancients 
equal  to  the  square  of  the  addition. 

118.  Example:  Tell  promptly  the  sum  of  the  squares,  and  the  sum  of 
the  cubes,  of  those  numbers,  if  thy  mind  be  conversant  with  the  way  of 
summation. 

Statement:     12345678  9- 

Answer  :     Sum  of  squares  285.     Sum  of  the  cubes  2025.* 

119-  Rule:'  The  increase  multiplied  by  the  period  less  one,  and  added 
to  the  first  quantity,  is  the  amount  of  the  last.*    That,  added  to  the  first, 

'  To  find  the  sums  of  squares  and  of  cubes.     Sua,  and  Gan. 

»  Sums  of  the  squares,  1     5     14     30       55       9i        140     204       285. 
Sums  of  the  cubes,     1     9     36     100     225     441     784     1296     2025. 

'  Where  the  increase  is  arbitrary. — Gakg.  In  such  cases,  to  find  the  last  term,  moan  amount, 
and  sura  of  the  progression. — Su'r.  From  first  term,  common  difference  and  period,  to  find  the 
whole  amount,  &c. — Gan. 

♦  Adi,  and  muc'ha,  xadana,  vactra,  and  other  synonyma  of  face  ;  the  initial  quantity  of  the  pro- 
gression ;  (that,  from  which  as  an  origin  the  sequence  commences. — Su'r.)  the  first  term. 

Chaya,  prachaya  OT  nttara  ;  the  more  (urf'Aica. — Su'r.)  or  siusvaent  (vrldd'hi. — Gang.)  by  which 
each  term  increases  :  the  common  increase  or  difference  of  the  terms. 

Antya  ;  the  last  term. 

Mad'hya  ;  the  middle  term,  or  the  mean  of  the  progression. 

Pada  or  gach'ha ;  the  period  (so  many  days  as  the  sequence  reaches. — Si/r.)  the  number  of 
terms. 

Saroord'hana,  Sred'hi-phala  or  Gariita ;  the  amount  of  the  whole ;  the  sum  of  the  progression.. 
'  It  is  called  gan'iVa,  because  it  is  found  by  computation  (gaiiani).'    Gan. 


Sect.  I.  PROGRESSION.  55 

and  halved,  is  the  amount  of  the  mean  :  Avhich,  multiplied  by  the  period,  is 
the  amount  of  the  wh6le,  and  is  denominated /"^a/i/Va^  the  computed  sum.' 

120.  Example  :  A  person,  having  given  four  di'ammas  to  pripsts  on  the 
first  day,  proceeded,  my  friend,  to  distribute  daily  alms  at  a  rate  increasing 
by  five  a  day.  Say  quickly  how  many  were  given  by  him  in  half  a 
month  ? 

Statement:     Initial  quant.  4;  Com.  diff;  5  ;  Period  15. 

Here,  First  term  4.     Middle  term  39.     Last  term  74.     Sum  585. 

121.  Example:*  The  initial  term  being  seven,  the  increase  five,  and 
the  period  eight,  tell  me,  what  are  the  numbers  of  the  middle  and  last 
amounts?     And  what  is  the  total  sum? 

Statement :     First  term  7  ;  Com.  diff;  5  ;  Period  8. 

Answer:     Mean  amount  *-^.     Last  term  42.     Sum  196. 

Here,  the  period  consisting  of  an  even  number  of  days,  there  is  no  middle 
day  :  wherefore  the  half  of  the  sum  of  the  days  preceding  and  following  the 
mean  place,  must  be  taken  for  the  mean  amount :  and  the  rule  is  thus 
proved. 

122.  Rule:'  half  a  stanza.  The  sum  of  the  progression  being  divided 
by  the  period,  and  half  the  common  difference  multiplied  by  one  less  than 
the  number  of  terms,  being  subtracted,  the  remainder  is  the  initial  quantity.* 

123.  We  know  the  sum  of  the  progression,  one  hundred  and  five;  the 
number  of  terms,  seven ;  the  increase,  three ;  tell  us,  dear  boy,  the  initial 
quantity. 


'  The  rule  is  founder!  on  the  proportion  ;  as  one  day  is  to  the  increase  of  one  day,  or  common 
difference,  so  is  the  number  of  increasing  terms  to  the  total  increase:  which,  added  to  the  initial 
quantity,  gives  the  last  term.  Sun.  &c. 

^  To  exhibit  an  instance  of  an  even  number  of  terms;  where  there  can  consequently  be  no 
middle  term  [but  a  mean  amount].  Gan. 

'  The  difference,  period  and  sum  being  given,  to  find  the  first  term.  Gan.  Sx/r. 

♦  The  rule  is  converse  of  the  preceding.  Gan.  and  Sur. 


54  ...LIXA'VATI'.  Chapter  V. 

Statement:     First  term?      Com.  difF.  3  ;    Period  7;    Sum  105. 
Answer  :     First  tenn,  6. 

Rule:'  half  a  stanza.*  The  sum  being  divided  by  the  period,  and  the 
first  term  subtracted  from  the  quotient,  the  remainder,  divided  by  half  of 
one  less  than  the  number  of  terms,  will  be  the  common  difference.' 

124.  Example:  On  an  expedition  to  seize  his  enemy's  elephants,  a 
king  marched  two  yojanas  the  first  day.  Say,  intelligent  calculator,  with 
what  increasing  rate  of  daily  march  did  he  proceed,  since  he  reached  his 
foe's  city,  a  distance  of  eighty  yojanas,  in  a  week  ? 

Statement :     First  term  2 ;  Com.  diff.  ?  Period  7 ;    Sum  80. 
Answer:  Com.  diff.  V- 

125.  Rule:*  From  the  sum  of  the  progression  multiplied  by  twice  the 
common  increase,  and  added  to  the  square  of  the  difference  between  the 
first  term  and  half  that  increase,  the  square  root  being  extracted,  this  root 
less  the  first  term  and  added  to  the  [above-mentioned]  portion  of  the  increase, 
being  divided  by  the  increase,  is  pronounced'  to  be  the  period. 

126.  Example :  A  person  gave  three  drammas  on  the  first  day,  and 
continued  to  distribute  alms  increasing  by  two  [a  day] ;  and  he  thus  bestowed 
on  the  priests  three  hundred  and  sixty  drammas :  say  quickly  in  how  many 
days? 

Statement :     First  term  3 ;  Com.  diff.  2  ;   Period?  Sum  360. 
Answer:     Period  18. 

'  The  first  term,  period  and  sum  being  known,  to  find  the  common  difference  which  is 
unknown.  Gan. 

*  Second  half  of  one,  the  first  half  of  which  contained  the  preceding  rule.  §  22. 

'  This  rule  also  is  converse  of  the  foregoing.  Gan. 

♦  The  first  term,,  commoa  difference  and  sum  being  known,  to  find  the  period  which  i» 
unknown.  Gan. 

'  By  Brahmegupta  and  the  rest. — Gan,  See  Brahm.  c.  12,  k  18.  and  Gan.  s6r,  of  Sr^d'h. 
%  123.  The  rules  are  substantially  the  same  ;  the  square  being  completed  for  the  solution  of  the 
quadratic  equation  in  the  manner  taught  by  s'rid'kara  (cited  in  Fyo-ga/w/a  §  131)  and  by 
Brahmegupta  c.  8.  §  32—33. 


(    55    ) 


SECTION    II. 

GEOMETRICAL   PROGRESSION. 

1 27.  Rule : '  a  couplet  and  a  half.  The  period  being  an  uneven  number 
subtract  one,  and  note  "  multipHcator;"  being  an  even  one,  halve  it  and 
note  "square:"  until  the  period  be  exhausted.  Then  the  produce  arising 
from  multiplication  and  squaring  [of  the  common  multiplier]  in  the  inverse 
order  from  the  last,'  being  lessened  by  one,  the  remainder  divided  by  the 
common  multiplier  less  one,  and  multiplied  by  the  initial  quantity,  will  be 
the  sura  of  a  progression  increasing  by  a  common  multiplier.' 

128.  Example  :  A  person  gave  a  mendicant  a  couple  of  cowry  shells 
first;  and  promised  a  two-fold  increase  of  the  alms  daily.  How  many 
nishcas  does  he  give  in  a  month  } 

Statement:     First  term,  2;  Two-fold  increase,  2;  Period  30 

Answer,  2 1474S36i6  cowries;   or  104857  nishcas,  9  drammas,  9  panas 
2  cacims,  and  6  shells.  ' 

'To  find  the  sum  of  a  progression,  the  increase  being  a  muItiplier.-GAK.  That  is,  the  sum  or 
an,ncreas,ng  geometrical  progression.  The  rule  agrees  with  PH>x'Ht/i,ACA's.  (See  Com  on 
Brahmegupta,  c.  12,  §  17.)     It  is  borrowed  from  prosody  (ibid) 

J  The  last  note  is  of  course  «  muhipiicator:"  for  in  e.xhausting  the  number  of  the  period,  you 
arnve  at  last,  at  un.ty  an  uneven  number.  The  proposed  multiplier  [the  common  multiplicator  of 
the  progress-on]  .s  therefore  put  in  the  last  place;  and  the  operations  of  squaring  and  multiplying 
by^it,  are  continued  m  the  inverse  order  of  the  line  of  the  notes.  Gan' 

»  The  effect  of  squaring  and  multiplying,  as  directed,  is  the  same  with  the  continued  multipli- 
cation  of  the  mu  fplier  for  as  many  times  as  the  number  of  the  period.  For  dividing  by  the  " 
mulfpher  the  product  of  the  multiplication,  continued  to  the  uneven  number,  equals  the  product 
ot  mu  .■pl.cai.on  continued  to  one  less  than  the  number;  and  the  extraction  of  the  square  root  of 
aproduct  of  multiphcation,  continued  to  the  even  number,  equals  continued  multiplication  to  half 
that  number.  Conversely,  squaring  and  multiplying  equals  multiplication  for  double  and  for  one 
more  time. 

Gan. 


56  LI'LA'VATI'.  Chapter  V. 

129.  Example:  The  initial  quantity  being  two,  my  friend;  the  daily 
augmentation,  a  three-fold  increase;  and  the  period,  seven;  say  what  is  in 
this  case  the  sum  ? 

Statement:     First  term,  2;  three-fold  increase,  3;  Period,  7. 
Answer:     2186. 

130 — 131.     Rule:*   a  couplet  and  an  half. 

The  number  of  syllables  in  a  verse  being  taken  for  the  period,  and  the 
increase  two-fold,  the  produce  of  multiplication  and  squaring  [as  above 
directed  §  127]  will  be  the  number  [of  variations]  of  like  verses.  *  Its  square, 
and  square's  square,  less  their  respective  roots,  will  be  [the  variations]  of 
alternately  similar,  and  of  dissimilar  verses  [in  tetrastics].' 

132.  Example:  Tell  me  directly  the  number  [of  varieties]  of  like, 
alternately  like,  and  dissimilar  verses,  respectively,  in  the  metre  named 
anushtubh.* 


•  Incidently  introduced  in  this  place,  showing  a  computation  serviceable  in  prosody. — Sua.  and 
Mono.  To  calculate  the  variations  of  verse,  which  also  are  found  by  the  sum  of  permutalion* 
[§  113].— Gan. 

*  Sanscrtt  prosody  distinguishes  metre  in  which  the  four  verses  of  the  stanza  are  alike  ;  or  the 
alternate  ones  only  so  ;  or  all  four  dissimilar.     Asiat.  Res.  vol.  10,  Syn.  tab.  v.  vi.  &  vii. 

'  The  number  of  possible  varieties  of  verse  found  by  the  rule  of  permutation  [§  113]  is  the  same 
with  the  continued  multiplication  of  two  :  this  number  being  taken,  because  the  varieties  of  syllables 
are  so  many;  long  and  short.  Accordingly  this  is  assumed  for  the  common  multiplier.  The 
product  of  its  continued  multiplication  is  to  be  found  also  by  this  method  of  squaring  and  multi- 
plying  [§  127]  ;  assuming  for  the  period  a  number  equal  to  that  of  syllables  in  the  vei-se.  The 
varieties  of  alternately  similar  verse,  arc  the  same  with  those  of  an  uniform  verse  containing  twice 
as  many  syllables ;  and  the  changes  in  four  dissimilar  verses  are  the  same  with  those  of  one  verse 
comprising  four  limes  as  many  syllables:  excepting,  however,  that  these  permutations,  embracing 
all  the  possible  varieties,  comprehend  those  of  like  and  half-alike  metre.  Wherefore  ihe  number 
first  found  is  squared,  and  this  again  squared,  for  twice,  or  four  times,  the  number  of  places ; 
and  the  roots  of  these  squares  subtracted,  for  the  permutations  of  like  and  alternately  like 
verses.  Gan'.  &c. 

The  product  of  multiplication  and  squaring  is  the  amount  of  the  last  term  of  the  progression, 
(the  first  term  and  common  multiplier  being  equal). 

♦  As.  Res.  vol.  10,  p.  438,  (Syn.  tab.)  p.  469.  Uano. 


Sect.  II. 


PROGRESSION. 


57 


Statement :     Increase  two-fold,  2 ;   Period,  8. 

Answer:     Variations  of  like  verses,   Q56 ;   of  alternately   alike   verses, 
65280;  of  dissimilar  verses,  4294901760.' 


'  Possible  varieties  of  the  four  verses  of  a  tetrastic  containing  32  syllables  (8  to  a  verse)  are 
4294967296  [2  raised  to  its  32d  power]:  of  which  4294901/60  are  dissimilar;  and  65536 
[2  raised  to  its  1 6th  power]  similar:  whereof  65280  alternately  alike ;  and  256  [2  raised  to  its 
eighth  power]  wholly  alike. — Mono,  &c. 


CHAPTER  VI. 


FLANE    FIGURE.' 


133.     Rule  :  A  side  is  assumed.*    The  other  side,  in  the  rival  direction,  is 

•  CshitrO'VyavaMra,  determination  of  plane  figure.  CsMfra,  as  expounded  by  Gan'es'a,  signi- 
fies plane  surface,  bounded  by  a  figure ;  as  triangle,  &c.  Vyavah&ra  is  the  ascertainment  of  its 
dimensions,  as  diagonal,  perpendicular,  area,  &c. 

Ranganat'ha  distinguishes  the  sorts  of  plane  figure,  precisely  as  the  commentator  of  Brah- 
MEGUPTA.     See  Chat,  on  Brahm.  12,  §21.     Gan'esa  says  plane  figure  is  four-fold;  triangle, 
quadrangle,  circle  and  bow.    Triangle  (trt/asra,  tricona  or  tribhuja)  is  a  figure  containing  (tri) 
three  (asra  or  cona)  angles,   and  consisting  of  as  many   (bhuja)   sides.     Quadrangle  or  tetragon 
(chaturasra,  chaturc&na,  chaturbhvja)   is  a  figure  comprising  (chatur)  four  (asra,  &c.)  angles  or 
sides.    The  circle  and  bow  (he  observes)  need  no  definition.     Triangle  is  either  (j&tya)  rectangu- 
lar, as  that  which  is  first  treated  of  in  the  text;  or  it  is  (tribhvja)  trilateral  [and  oblique]  like  the 
fruit  of  the  Sringtita  (TrapA  natans).     This  again  is  distinguished  according  as  the  (lamba)  per- 
pendicular falls  within  or  without  the  figure :  viz.  antar-lamba,  acutangular ;  bahirlamba,  obtusan- 
gular.     Quadrangle  also  is  in  the  first  place  twofold:  with  equal,  or  with  unequal,  diagonals.    The 
first  of  these,  or  ecjui-diagonal  tetragon  (sama-cartia)  comprises  four  distinctions  :  1st.  sama-chatur- 
bhuja,  equilateral,   a  square  ;     2d.  vishama-chaturbhija,  a  trapezium  ;    3d.  dyaia-dirgha-chatiirasra, 
oblong  quadrangle,   an  oblique  parallelogram  ;  4th,  6i/ata-sama-laniba,   oblong  with  equal  perpen- 
diculars ;  that  is,  a  rectangle.     The  second  sort  of  quadrangle,  or  the  tetragon  with  unequal  dia- 
gonals,  (vishama-carna,)  embraces  six  sorts:  1st.  sama-chaturbhuja,   equilateral,   a  rhomb;  2d. 
sama-tribkuja,  containing  three  sides  equal ;  3d.  sama-did-dvii-bhuja,  consisting  of  two  pairs  of  equal 
sides,  a  rhomboid  ;  4th.  smna-dm-bhuja,  having  two  sides  equal ;    5th.  vishama-chaturbhuja,  com- 
posed of  four  unequal  sides,  a  trapezium  ;    6ih.  sama-lamba,   having  equal  perpendiculars,  a  trape- 
zoid.   The  several  sorts  of  figures,  observes  the  commentator,  are  fourteen  ;  the  circle  and  bow 
being  but  of  one  kind  each.     He  adds,   that  pentagons  CpanchHsraJ,  &c.  comprise  triangles  [and 
are  reducible  to  them]. 

*  Bdhu,  dosh,  bhuja  and  other  synonyma  of  arm  are  used  for  the  leg  of  a  triangle,   or  side  of  a 
quadrangle  or  polygon :  so  called,  as  resembling  the  human  arm.  Gan.  and  Su/i. 


PLANE   FIGURE.  59 

called  the  upright,'  whether  in  a  triangle  or  tetragon,  by  persons  conversant 
with  the  subject. 

134.  The  square-root  of  the  sum  of  the  squares  of  those  legs  is  the  diago- 
nal.- The  square-root,  extracted  from  the  difference  of  the  squares  of  the 
diagonal  and  side,  is  the  upright:  and  that,  extracted  from  the  difference  of 
the  squares  of  the  diagonal  and  upright,  is  the  side.-' 

135.*  Twice  the  product  of  two  quantities,  added  to  the  square  of  their 
difference,  will  be  the  sum  of  their  squares.  The  product  of  their  sum  and 
difference  will  be  the  difference  of  their  squares :  as  must  be  every  where 
understood  by  the  intelligent  calculator.' 

136.  Example.  Where  the  upright  is  four  and  the  side  three,  what  is 
the  hypotenuse.?  Tell  me  also  the  upright  from  the  hypotenuse  and  side; 
and  the  side  from  the  upright  and  hypotenuse. 


^ 


Statement:  4[_^     Side  3;    Upright  4.     Sum  of  their  squares  25.      Or 


'  Either  leg  being  selected  to  retain  this  appellation,  the  others  are  distinguished  by  different  de- 
nominations. That,  which  proceeds  in  the  opposite  direction,  meaning  at  right  angles,  is  called 
coti,  uchch'hraya,  vchch'hriti,  or  any  other  term  signifying  upright  or  elevated.  Both  are  alike 
sides  of  the  triangle  or  of  the  tetragon,  differing  only  in  assumed  situation  and  name.— Gan.  and 
Sc'r.     The  coti  or  upright  is  the  cathetus. 

""  A  thread  or  oblique  line  from  the  two  extremities  of  the  legs,  joining  them,  is  the  carna,  also 
termed  iruti,  sravana,  or  by  any  other  words  importing  ear.  It  is  the  diagonal  or  diameter  of  a 
tetragon.— Sua.  Rang.  &c.  Or,  in  the  case  of  a  triangle,  it  is  the  diagonal  of  the  parallelogram, 
whereof  the  triangle  is  the  half:  and  is  the  hypothenuse  of  a  right-angled  triangle. 

'  The  rule  concerns  (jYifj/aJ  rectangtilar  triangles.  The  proof  is  given  both  algebraically  and 
geometrically*  by  Gan'e's'a;  and  the  first  demonstration  is  exhibited,  both  with  and  without  alge- 
bra, by  Sc'hyada's'a.  RanganaVha  cites  one  of  those  demonstrations  from  his  own  brother  Ca- 
mala'cara;  and  the  other  from  his  father  NafsiNHA,  in  the  V/irfica,  or  critical  remarks  on  the 
(V6$andJ  annotations  of  the  Siromarii ;  and  censures  the  Sring6ra-tilaca  for  denying  any  proof  of 
the  rule  besides  experience.  Bha'scara  has  himself  given  a  demonstration  of  the  rule  in  his 
algebraical  work.     Vij.  Gad.  §  146. 

*  A  stanza  of  six  verses  o(  anushtubh  metre. 

Ganesa  here  also  gives  both  an  algebraic  and  a  geometrical  proof  of  the  latter  rule;  and  an 
algebraical  one  only  of  the  first.  See  V'lj.  Gan.  under  §  148;  whence  the  latter  demonstration  is 
borrowed  ;  and  §  147,  where  the  first  of  the  rules  is  given  an<l  demonstrated. 

•  Csh£tritgat6popaUi,  geoinrtrical  deraoiistration. 
UpapatU  ttiyacta-criyayd,  proof  by  algebra. 


eo  LIXAVATI.  Chapter  VL 

product  of  the  sides,  doubled,  24 ;   square  of  the  difference  1 :    added  to- 
gether, 25.     Tlie  square-root  of  this  is  the  hypotenuse  5. 

j\^      Difference  of  the  squares  [of  5  and  3]  \6.     Or  suhfi  8,   multiplied 

3 

by  the  difference  2,  makes  \6.     Its  square-root  is  the  upright  4. 

4  \^      Difference  of  squares,  found  as  before,  9.  Its  square  root  is  the  side  3. 

''137.  Example.  Where  the  side  measures  three  and  a  quarter;  and  the- 
upright,  as  much ;  tell  me,  quickly,  mathematician,  what  is  the  length  of  the 
hypotenuse  r 


Statement:     V|  \^     Sum  of  the  squares  V/  o""  *f'-     Since  this  has  no 

V 
[assignable]  root,  the  hypotenuse  is  a  surd.     A  method  of  finding  its  approx- 
imate root  [follows :]. 

138.  Rule:  From  the  product  of  numerator  and  denominator,*  multiplied 
by  any  large  square  number  assumed,  extract  the  square-root :  that,  divided 
by  the  denominator  taken  into  the  root  of  the  multiplier,  will  be  an  approx- 
imation.* 

This  irrational  hypotenuse  »^»  [is  proposed].  The  product  of  its  nume- 
rator and  denominator  is  1352.  Multiplied  by  a  myriad  (the  square  of  a 
hundred),  the  product  is  23520000.  Its  root  is  3677  nearly.'  This  divided 
by  the  denominator  taken  into  the  square-root  of  the  multiplier,  viz.  800, 
gives  the  approximate  root  4  -|^.  It  is  the  hypotenuse.  So  in  every  simi- 
lar instance. 

'  If  the  surd  be  not  a  fraction,  unity  raay  be  put  for  the  denominator,  and  the  rule  holds  good. 

Gan. 

*  Here  two  quantities  are  assumed:  the  denominator  and  the  arbitrary  square  number.  The 
multiplication  of  the  numerator  by  the  denominator  is  equivalent  to  the  multiplication  of  the  frac- 
tion by  the  denominator  twice;  that  is,  by  the  square  of  the  denominator.  The  surd,  having  been 
thus  multiplied  by  that  and  the  arbitrary  number,  both  squares,  the  square-root  of  the  product  is 
divided  by  the  denominator  and  by  the  root  of  the  arbitrary  number.  The  quotient  is  the  root  o£ 
the  irrational  quantity. — Gan.  &c.  A  like  rule  occurs  in  Srid'iiara's  compendium. — Gan,  sdr~ 
§  138. 

'  The  remainder  being  unnoticed. 


I 


PLANE    FIGURE.  61 

139.  Rule.*  A  side  is  put.  From  that  multiplied  by  twice  some  assumed 
number,  and  divided  by  one  less  than  the  square  of  the  assumed  number,  an 
upright  is  obtained.  This,  being  set  apart,  is  multiplied  by  the  arbitrary 
number,  and  the  side  as  put  is  subtracted  ;  the  remainder  will  be  the  hypo- 
tenuse.    Such  a  triangle  is  termed  rectangular. 

140.  Or  a  side  is  put.  Its  square,  divided  by  an  arbitrary  number,  is  set 
down  in  two  places :  and  the  arbitrary  number  being  added  and  subtracted, 
and  the  sum  and  difference  halved,  the  results  are  the  hypotenuse  and  up- 
right. Or,  in  like  manner,  the  side  and  hypotenuse  may  be  deduced  from 
the  upright.     Both  results  are  rational  quantities. 

141.  Example.  The  side  being  in  both  cases  twelve,  tell  quickly,  by 
both  methods,  several  uprights  and  hypotenuses,  which  shall  be  rational 
numbers. 

Statement:  Side  12.  Assumptions.  The  side,  multiplied  by  twice  that, 
viz.  4,  is  48.  Divide  by  the  square  of  the  arbitrary  number  less  one,  viz.  3, 
the  quotient  is  the  upright  16.  This  upright,  multiplied  by  the  assumed 
number,  is  32 :  from  which  subtract  the  given  side,  the  remainder  is  the  hy- 
potenuse 20.      See 


12 
Assume  three.     The  upright  is  9;  and  hypotenuse  15.     Or,  putting  five, 
the  upright  is  5,  and  hypotenuse  13. 

'  Either  the  side  or  upright  being  given,  to  find  the  other  two  sides. — Sua.  To  find  the  up- 
right and  hypotenuse,  from  the  side;  or  the  side  and  hypotenuse  from  the  upright. — Gav.  The 
problem  is  an  indeterminate  one,  as  is  intimated  by  the  author.  The  second  rule  is  in  substance 
the  same  with  Braiimegufta's  for  the  upright  and  diagonal  of  a  rectangle.  See  Braiim.  1?, 
§35. 

Su'ryada'sa  demonstrates  the  first  rule  thus:  '  In  some  triangle  (which  should  be  less  than  that 
which  has  the  given  side)  the  upright  is  taken  at  double  of  some  assumed  number,  and  the  side  is 
taken  at  one  less  than  the  assumed  number.  Then  make  proportion,  "  as  this  side  to  this  upright, 
so  is  the  given  side  to  its  upright."  Whence  the  given  side,  multiplied  by  twice  the  assumed  num- 
ber, and  divided  by  one  less  than  its  square,  is  the  upright.  When  this  upright  so  found  is  muN 
tiplied  by  the  assumed  number,  the  product  is  the  sum  of  the  side  and  hypotenuse  :  when  divided 
by  it,  the  quotient  is  the  difl'erence  of  the  side  and  hypotenuse  :  for  they  increase  and  decrease  by 
virtue  of  that  assumed  number.  Thus,  subtracting  the  given  side  from  that  sum,  the  remainder  is 
the  hypotenuse  :  or,  adding  it  to  the  difference,  the  sum  is  the  hypotenuse.  Su'r. 


62  Ll'LAVATl'.  Chapter  VI. 

By  the  second  method:  the  side,  as  put,  12.  Its  square  144.  Divide  by 
2,  the  arbitrary  number  being  two,  the  quotient  is  72.  Add  and  subtract 
the  arbitrary  number,  and  halve  the  sum  and  diflFerence :  the  hypotenuse  and 
upright  are  found :  viz.  upright  35,  hypotenuse  37.     See 


12 

Assume  four.  The  upright  is  16,  and  hypotenuse  20.  Assuming  six,  the 
upright  is  9  and  hypotenuse  15.* 

142.  Rule  :*  Twice  the  hypotenuse  taken  into  an  arbitrary  number,  being 
divided  by  the  square  of  the  arbitrary  number  added  to  one,  the  quotient  is 
the  upright.  This  taken  apart  is  to  be  multiplied  by  the  number  put :  the 
diiference  between  the  product  and  the  hypotenuse  is  the  side.' 

143.  Example:  Hypotenuse  being  measured  by  eighty-five,  say 
promptly,  learned  man,  what  uprights  and  sides  will  be  rational  ? 

Statement:  The  hypotenuse  85,  being  doubled,  is  170;  and  multiplied 
by  an  arbitrary  number  two,  is  340.     This,  divided  by   the  square  of  the 

The  demonstration  of  the  second  method  is  given  by  Gan:^sa',  and  similarly  by  Su'rtada'sa 
and  RanganaVha.  '  Assume  any  number  for  the  difference  between  the  uprightand  hypotenuse. 
The  difference  of  their  squares  (which  is  equal  to  the  square  of  the  given  side)  being  divided  by 
that  assumed  difference,  the  quotient  is  the  sum  of  the  upright  and  hypotenuse.  For  the  difference 
of  the  squares  is  equal  to  the  product  of  the  sum  and  difference  of  the  roots.  (§  135.)  The  upright 
and  hypotenuse  are  therefore  found  by  the  rule  of  concurrence'  (§  55).  Gan.  &c. 

'  In  like  manner,  if  the  upright  be  given,  l6.  Its  square  256,  divided  by  the  arbitrary  number 
2,  is  128.  The  arbitrary  number  subtracted  and  added,  makes  126  and  130;  which  halved  gives 
the  side  63  and  hypotenuse  65.  Gang,  and  Sua. 

"  From  the  hypotenuse  given,  to  find  the  side  and  upright  in  rational  numbers. — Gan.  The 
problem  is  an  indeterminate  one. 

'  Let  the  upright  in  a  figure  be  any  assumed  number  doubled  ;  and  the  hypotenuse  be  unity  added 
to  the  square  of  that  arbitrary  number.  Thence  a  proportion,  as  before  :  If  with  this  hypotenuse, 
this  upright ;  then  with  the  given  hypotenuse,  what  is  the  upright?  It  is  consequently  found  :  viz. 
twice  the  given  hypotenuse  multiplied  by  the  arbitrary  number,  and  divided  by  the  square  of  that 
number  with  unity  added  to  it.  If  that  be  multiplied  by  the  arbitrary  number,  the  product  is  the 
sum  of  the  hypotenuse  and  side  ;  if  divided  by  it,  their  difference.  Hence,  by  the  rule  of  concui<- 
rence  (§  55),  the  side  and  hypotenuse  are  found.  But  here,  for  brevity,  the  hypotenuse, being  already 
known,  is  subtracted  from  the  sum  of  that  and  the  side.  Su  a. 


.:  /  iiar-i/  i;^ 


PLANE   FIGURE. 


65 


arbitrary  number  added  to  one,  viz.  5,  is  the  upright  68.  This  upright, 
multiplied  by  the  arbitrary  number,  makes  136:  and  subtracting  the  hypo- 
tenuse, the  side  comes  out  51.     See     N 

68  \85 

51 

Or  putting  four,  the  upright  will  be  40;    and  side  75.     See  40p'-^ 

75 

144.  Rule :  Or  else  hypotenuse  is  doubled  and  divided  by  the  square 
of  an  assumed  number  added  to  one.  Hypotenuse,  less  that  quotient,  is  the 
upright.  The  same  quotient,  multiplied  by  the  assumed  number,  is  the 
side.* 

The  same  hypotenuse  85.  Putting  two,  the  upright  and  side  are  51  and 
68.     Or,  with  four,  they  are  75  and  40. 

Here  the  difference  between  side  and  upright  is  in  name  only,  and  not 
essential. 

145.  Rule:*  Let  twice  the  product  of  two  assumed  numbers  be  the 
upright;  and  the  difference  of  their  squares,  the  side:  the  sum  of  their 
squares  will  be  the  hypotenuse,  and  a  rational  number.' 


'  The  assumed  upright  in  the  small  triangle  was  before  taken  at  twice  a  number  put.  The 
assumption  is  now  two,  and  hypotenuse  is  put  as  there  stated.  Then  proportion  being  made  as 
before,  the  quotient  is  multiplied  by  the  arbitrary  number,  because,  in  comparison  with  the  preced- 
ing, It  was  just  so  much  less.  The  quotient,  as  it  comes  out,  is  the  difference  between  the  hypo- 
tenuse and  side:  and,  that  being  subtracted  from  the  hypotenuse,  the  residue  is  the  side.-SuR. 
This  and  the  preceding  rule  are  founded  on  the  same  principle ;  differing  only  in  the  order  of  the 
operation  and  names  of  the  sides:  the  same  numbers  come  out  for  the  side  and  upright  in  one 
mode,  which  were  found  for  the  upright  and  side  by  the  other. 

«  Having  taught  the  mode  of  finding  a  third  side,  from  any  two,  of  hypotenuse,  upright  and  side ; 
and  in  like  manner  from  one,  the  other  two;  the  author  now  shows  a  method  of  findin«  all  three 
rational  [none  being  given.]-GAN.     The  problem  is  an  indeterminate  one. 

'  The  demonstration  is  by  resolution  of  a  quadratic  equation  involving  several  unknown  :  Let 
the  length  of  the  side  be  ya  ],  and  that  of  the  upright  cal.  The  sum  of  their  squares  is  j/as  1  cor,  1. 
It  is  a  square  quantity.  Putting  it  equal  to  „iv  1,  the  root  of  this  side  of  the  equation  is  ni  1 ;  and 
those  of  the  other  side  are  to  be  found  by  the  rule  of  the  affected  square*  Assuming  either  term 
for  the  affected  square,  the  other  will  be  the  additive.  I^t  yavihe  the  proposed  square,  and  ca  v  1 
the  additive.  Then  the  coefficient  being  a  square,  the  roots  are  to  be  found  by  the  rule  {Vij.  g/,n. 
h  95).     Here  a  fraction  of  ca  is  put ;  an  arbitrary  number  for  the  numerator,  and  another  arbitrary 

•  yH-  gan.  ch.  3. 


64  LI'LAVATI'.  Chapter  VI. 

146.  Example.  Tell  quickly,  friend,  three  numbers,  none  being  given, 
with  which  as  upright,  side  and  hypotenuse,  a  rectangular  triangle  may  be 
[constructed.] 

Statement.  Let  two  numbers  be  put,  1  and  2.  From  these  the  side,  up- 
right and  hypotenuse  are  found,  4,  3,  5.  Or,  putting  2  and  3,  the  side,  up- 
right and  hypotenuse  deduced  from  them,  are  12,  5,  13.  Or  let  the  assumed 
numbers  be  2  and  4:  from  which  will  result  16,  12,  20.  In  like  manner, 
manifold  [answers  are  obtained]. 

147.  Rule^.  The  square  of  the  ground  intercepted  between  the  root  and 
tip,  is  divided  by  the  [length  of  the]  bambu;  and  the  quotient  severally 
added  to,  and  subtracted  from,  the  bambu  :  the  moieties  [of  the  sum  and 
difference]  will  be  the  two  portions  of  it  representing  hypotenuse  and  up- 
right.* 

148.  Example.'  If  a  bambu,  measuring  thirty-two  cubits  and  standing 
upon  level  ground,  be  broken  in  one  place,  by  the  force  of  the  wind,  and 

one  for  the  denominator.  For  instance  ca  f.  Then  by  the  method  taught  {Vij.  gan.  §  95)  the 
least  and  greatest  roots  come  out  ca  -^,  ca  -J^  Here,  in  the  place  of  the  numerator  of  the  least  root, 
is  the  difi'erence  of  the  squares  ol  the  assumed  numbers;  and,  in  that  of  the  denominator,  twice  their 
product.  So,  in  place  of  the  numerator  of  the  greatest  root,  is  the  sum  of  the  squares  ;  and,  in 
that  of  the  denominator,  twice  the  product.  The  least  root  is  the  value  o(  i/a,  the  fraction  ca  -f^. 
Then,  by  the  pulverizer,*  the  multiplier  and  quotient  come  out  5  and  12.  The  multiplier  is  the 
value  oi ya  and  is  the  side.  The  quotient  is  the  value  of  ca  and  is  the  upright  12.  Substituting 
with  it  for  ca  in  the  greatest  root,  this  is  found  13.  It  is  the  value  of  ni  and  is  the  hypotenuse. 
Thus  the  side,  upright  and  hypotenuse  are  obtained  5,  12,  13.  This  is  the  operation  directed  by 
the  rule,  §145.  Gan. 

'  The  sum  of  hypotenuse  and  upright  being  known,  as  also  the  side,  to  discriminate  the  hy- 
potenuse and  upright. — Gan.     The  rule  bears  reference  to  the  example  which  follows. 

*  The  height  from  the  root  to  the  fracture  is  the  upright.  The  remaining  portion  of  the  bambu 
is  hypotenuse.  The  whole  bambu,  therefore,  is  the  sum  of  hypotenuse  and  upright.  The  ground 
intercepted  between  the  root  and  tip  is  the  side  :  it  is  equal  to  the  square  root  of  the  difference 
between  the  squares  of  the  hypotenuse  and  upright.  Hence  the  sqiiare  of  the  side,  divided  by  the 
sum  of  the  hypotenuse  and  side,  is  their  difference  [§  135].  With  these  (sum  and  difference)  the 
upright  and  hypotenuse  are  found  by  the  rule  of  concurrence  (§  55).  Gan.  . 

'  See  Arithra.  of  Brahmeoupta  under  §  41 ;  and  Vij.-gaii.  §  124;  where  the  same  example 
occurs.  '  f 

•   Vija'gtmita,  ch.  2. 


PLANE   FIGURE.  m 

the  tip  of  it  meet  the  ground  at  sixteen  cubits  :  say,  mathematician,  at  how 
many  cubits  from  the  root  is  it  broken  ? 

Statement.  Bambu  32.  Interval  between  the  root  and  tip  of  the  bambu 
16.  It  is  the  side  of  the  triangle.  Proceeding  as  directed,  the  upper  and 
lower  portions  of  the  bambu  are  found  20  and  12.     See  figure 


20 

TO 

12 


^•-fo 


16 


149.  Rule.*  The  square  [of  the  height]  of  the  pillar  is  divided  by  the 
distance  of  the  snake  from  his  hole ;  the  quotient  is  to  be  subtracted  from 
that  distance.  The  meeting  of  the  snake  and  peacock  is  from  the  snake's 
hole  half  the  remainder,  in  cubits. - 

150.  Example.'  A  snake's  hole*  is  at  the  foot  of  a  pillar,  and  a  peacock 
is  perched  on  its  summit.  Seeing  a  snake,  at  the  distance  of  thrice  the  pil- 
lar, gliding  towards  his  hole,  he  pounces  obliquely  upon  him.  Say  quickly 
at  how  many  cubits  from  the  snake's  hole  do  they  meet,  both  proceeding  aa 
equal  distance  ? 

Statement.     Pillar  9.     It  is  the  upright.     Distance  of  the  snake  from  his 

hole  27.     It  is  the  sum  of  hypotenuse  and  side.     Proceeding  as  directed,  the 

meeting  is  found  in  cubits;  viz.  12.*     See  figure    qP^^ 

^12\    15 


27 

The  sum  of  the  side  and  hypotenuse  being  known,  as  also  the  upright,  to  discriminate  the 
hypotenuse  and  side.  Gan. 

*  The  rule  bears  reference  to  the  example  which  follows.  The  principle  is  the  same  with  that 
of  the  preceding  rule. 

*  This  occurs  also  in  some  copies  of  the  V'lja-ganita,  after  §  139  ;  as  appears  from  the  commen- 
tary of  Su'ryada'sa,  giving  an  interpretation  of  it  in  that  place.  It  is  borrowed  from  the  Arithm. 
of  Brahmegupta  under  §  41,  with  a  change  of  a  snake  and  a  peacock  substituted  for  a  rat  and 
a  cat. 

*  Subtracted  from  the  sum  of  hypotenuse  and  side,  this  leaves  15  for  the  hypotenuse.  The 
saake  had  proceeded  the  same  distance  of  15  cubits  towards  his  hole,  as  the  peacock  in  pouncing 
upon  him.    Their  progress  is  therefore  equal.  Su'r. 

K 


66i  LI'LA'VATI'.  Chapter  VI. 

151.  Rule.^  The  quotient  of  the  square  of  the  side  divided  by  the  dif- 
ference between  the  hypotenuse  and  upright  is  twice  set  down  :  and  the  dif- 
ference is  subtracted  from  the  quotient  [in  one  place]  and  added  to  it  [in  the 
other].  The  moieties  [of  the  remainder  and  sum]  are  in  their  order  the  up- 
right and  hypotenuse.*^ 

This'  is  to  be  generally  applied  by  the  intelligent  mathematician. 

152.  Friend,  the  space,  between  the  lotus  [as  it  stood]  and  the  spot 
where  it  is  submerged,  is  the  side.  The  lotus  as  seen  [above  water]  is  the 
difference  between  the  hypotenuse  and  upright.  The  stalk  is  the  upright:* 
for  the  depth  of  water  is  measured  by  it.  Say,  what  is  the  depth  of 
water  ? 

153.  Example.'  In  a  certain  lake  swarming  Avith  ruddy  geese*  and 
cranes,  the  tip  of  a  bud  of  lotus  was  seen  a  span  above  the  surface  of  the 
water.  Forced  by  the  wind,  it  gradually  advanced,  and  was  submerged  at 
the  distance  of  two  cubits.  Compute  quickly,  mathematician,  the  depth  of 
water. 

Statement:  Diff.  of  hypotenuse  and  upright  ^  cubit.  Side  2  cubits. 
Proceeding  as  directed,  the  upright  and  hypotenuse  are  found,  viz.  upright 
'/.  It  is  the  depth  of  water.  Adding  to  it  the  height  of  the  bud,  the  hy- 
potenuse comes  out  V  •     See 


154.     Rule.^     The  height  of  the  tree,  multiplied  by  its  distance  from  the 

'  The  difference  between  the  hypotenuse  and  upright  being  known,  as  also  the  side,  to  find  the 
xipright  and  hypotenuse.  Gan. 

*  The  demonstration,  distinctly  set  forth  under  a  preceding  rule,  is  applicable  to  this.     Gan. 
^  Beginning  from  the  instance  of  the  broken  bambu  (§  147)  and  including  what  follows.     Gai/. 

*  The  sides,  constituting  the  figure  in  the  example  which  follows,  are  here  set  forth,  to  assist 
the  apprehension  of  the  student.  Sun.  and  Gan. 

'  See  Arithm.  of  Buahm.  under  §  41 ;  and  V'tj.-gan.  ^  125:  where  the  same  example  is  in- 
serted. 

*  Anas  Casarca. 

'  The  sum  of  the  hypotenuse  and  upper  portion  of  the  upright  being  given,  and  the  lower  por- 
tion being  known;  as  also  the  side:  to  discriminate  the  portion  of  the  upright  from  the  hypote- 
nuse.— Gas'.  As  in  several  preceding  instances,  a  reference  to  the  example  is  requisite  to  the 
understanding  of  the  rule.  The  same  problem  occurs  in  BRAUMiic.urTA's  Arithmetic,  §  35  i  and 
is  repeated  in  the  Vija-ganila,  §  135. 


...J       ,  PLANE   FIGURE.  67 

pond,  is  divided  by  twice  the  height  of  the  tree  added  to  the  space  between 
the  tree  and  pond  :  the  quotient  will  be  the  measure  of  the  leap. 

155.  Example.  From  a  tree  a  hundred  cubits  high,  an  ape  descended 
and  went  to  a  pond  two  hundred  cubits  distant:  Avhile  another  ape,  vault- 
ing to  some  height  off  the  tree,  proceeded  with  velocity  diagonally  to  the 
same  spot.  If  the  space  travelled  by  them  be  equal,  tell  me,  quickly,  learned 
man,  the  height  of  the  leap,  if  thou  have  diligently  studied  calculation. 

Statement:  Tree  100  cubits.  Distance  of  it  from  the  pond  200.  Pro- 
ceediug  as  directed,  the  height  of  the  leap  comes  out  50.*     See      50K.  o 


100 


•?<? 


200 


156.  Rule.-  From  twice  the  square  of  the  hypotenuse  subtract  the  sum 
of  the  upright  and  side  multiplied  by  itself,  and  extract  the  square-root  of 
the  remainder.  Set  down  the  sum  twice,  and  let  the  root  be  subtracted  in 
one  place  and  added  in  the  other.  The  moieties  will  be  measures  of  the  side 
and  upright.' 

157-  Example.  Where  the  hypotenuse  is  seven  above  ten ;  and  the  sum 
of  the  side  and  upright,  three  above  twenty  ;  tell  them  to  me,  my  friend. 

Statement:  Hypotenuse  17-  Sum  of  side  and  upright  23.  Proceeding 
as  directed,  the  side  and  upright  are  found  6  and  15. 

15 

•  The  hypotenuse  is  250:  and  the  entire  upright  150. 

*  Hypotenuse  being  known,  as  also  the  sum  of  the  side  and  upright,  or  their  difference ;  to  dis- 
criminate those  sides.  Gan. 

'  In  like  manner,  the  difference  of  the  side  and  upright  being  given,  the  sanie  rule  is  appli- 
cable.— Gan.    Using  the  difference  instead  of  the  sum. 

The  principle  of  the  rule  is  this  :  the  square  of  the  hypotenuse  is  the  sum  of  the  squares  of  the 
sides.  But  the  sum  of  the  squares,  with  twice  the  product  of  the  sides  added  to  it,  is  the  square  of 
the  sum  ;  and,  with  the  same  subtracted,  is  the  square  of  the  difference.  Hence,  cancelling  equal 
quantities  affirmative  and  negative,  twice  the  square  of  the  hypotenuse  will  be  the  sum  of  the 
squares  of  the  sum  and  difference.  Therefore,  subtracting  from  twice  the  square  of  hypotenuse 
the  square  of  the  sum,  the  remainder  is  the  square  of  the  difference ;  or  conversely,  subtracting 
the  square  of  the  difference,  the  residue  is  the  square  of  the  sum.  The  square-root  is  the  sura  or 
the  difference.    With  these,  the  sides  are  found  by  the  rule  of  concurrence.         Gan.  and  Sub. 

K  2 


68 


LI'LAVATI'. 


Chapter  VT. 


158.  Example.  Where  the  difference  of  the  side  and  upright  is  seven 
and  hypotenuse  is  thirteen,  say  quickly,  eminent  mathematician,  what  are 
the  side  and  upright  r^ 

Statement.  Difference  of  side  and  upright  7-  Hypotenuse  13.  Pro- 
ceeding as  directed,  the  side  and  upright  come  out  5  and  12.     See 


12 


.13 


159.  Rule."  The  product  of  two  erect  bambus  being  divided  by  their 
sum,  the  quotient  is  the  perpendicular'  from  the  junction  [intersection]  of 
threads  passing  reciprocally  from  the  root  [of  one]  to  the  tip  [of  the  other.] 
The  two  bambus,  multiplied  by  an  assumed  base,  and  divided  by  their  sum, 
are  the  portions  of  the  base  on  the  respective  sides  of  the  perpendicular. 

160.  Example.*  Tell  the  perpendicular  drawn  from  the  intersection  of 
strings  stretched  mutually  from  the  roots  to  the  summits  of  two  bambus 
fifteen  and  ten  cubits  high  standing  upon  ground  of  unknown  extent. 

Statement:  Bambus  15,  10.     The  perpendicular  is  found  6. 

Next  to  find  the  segments  of  the  base :  let  the  ground  be  assumed  5  ;  the 
segments  come  out  3  and  2.  Or  putting  10,  they  are  6  and  4.  Or  taking 
15,  they  are  9  and  6.     See  the  figures 

15 


10 


3  2 


15 


10 


9      0' 


In  every  instance  the  perpendicular  is  the  same :  viz.  6* 

The  proof  is  in  every  case  by  the  rule  of  three  :  if  with  a  side  equal  to  tlie 


•  This  example  of  a  case  where  the  difference  of  the  sides  is  given,  is  omitted, by  Su'ryada'sa, 
but  noticed  by  Gan'esa.  Copies  of  the  text,  vary;  some  containing,  and  others  omitting,  the 
instance. 

^  Having  taught  fully  the  method  of  finding  the  sides  in  a  right-angled  triangle,  the  author  next 
propounds  a  special  problem. — Gan.     To  find  the  perpendicular,  the  base  being  unknown. — Su'r. 
^  Lamba,  Avalamba,  Valamha,  Ad'holamba,  the  perpendicular. 

•  See  Vija-ganita,  §  127. 

•  However  the  base  may  vary  by  assuming  a  greater  or  less  quantity  for  it,  the  perpendicular 
will  still  be  the  same.  Gan. 


PLANE   FIGURE.  69 

base,  the  bambu  be  the  upright,  then  with  the  segment  of  the  base  what 
will  be  the  upright?* 

161.  Aphorism.''  That  figure,  though  rectilinear,  of  which  sides  are  pro- 
posed by  some  presumptuous  person,  wherein  one  side^  exceeds  or  equals  the 
sum  of  the  other  sides,  may  be  known  to  be  no  figure. 

162.  Example:  Where  sides  are  proposed  two,  three,  six  and  twelve  in 
a  quadrilateral,  or  three,  six  and  nine  in  a  triangle,  by  some  presumptuous 
dunce,  know  it  to  be  no  figure. 

Statement :  The  figures  are  both  incongruous.  Let  strait  rods  exactly  of 
the  length  of  the  proposed  sides  be  placed  on  the  ground,  the  incongruity, 
will  be  apparent. 


4 


163 — 164.     Rule'  in  two  couplets:  In  a  triangle,  the  sum  of  two  sides, 
being  multiplied  by  their  difference,  is  divided  by  their  base  :*  the  quotient 

'  On  each  side  of  the  perpendicular,  are  segments  of  the  base  relative  to  the  greater  and  smaller 
bam  bus,  and  larger  or  less  analogously  to  them.  Hence  this  proportion.  "  If  with  the  sum  of  the 
bambus,  this  sum  of  the  segments  equal  to  the  entire  base  be  obtained,  then,  with  the  smaller 
bambu,  what  is  had  ?"  The  answer  gives  the  segment,  which  is  relative  to  the  least  bambu 
Again:  "  if  with  a  side  equal  to  the  whole  base,  the  higher  bambu  be  the  upright,  then  with  aside 
eciual  to  the  segment  found  as  above,  what  is  had  i"  The  answer  gives  the  perpendicular  let  fall 
from  the  intersection,  of  the  threads.  Here  a  multiplicator  and  a  divisor  equal  to  the  entire  base 
are  both  cancelled  as  equal  and  contrary;  and  there  remain  the  product  of  the  two  bambus  for 
numerator  and  their  sura  for  denominator.     Hence  the  rule.  Gan. 

The  aphorism  explains  the  nature  of  impossible  figures  proposed  by  dunces. — Su'r.  It  serves 
as  a  definition  of  plane  figure  (cshitra). — Gan.  In  a  triangle  or  other  plane  rectilinear  figure, 
one  side  is  always  less  than  the  sum  of  the  rest.  If  equal,  the  perpendicular  is  nought,  and  there 
is  no  complete  figure.  If  greater,  the  sides  do  not  meet. — Su'r.  Containing  no  area,  it  is  no 
figure.— CawOT.  Rang. 

'  The  principal  or  greatest  side. — Gan.     Caz«».  Rang. 

*  The  rods  will  not  meet. — Su'r. 

'  In  any  triangle  to  find  the  perpendicular,  segments  and  area.    This  is  introductory  to  a  fullec 
consideration  of  areas.— Gan.  and  Sua.     It  is  taken  from  Brahmegupta,  12,  §  22. 

Bhumi,  bhu,  cu,  ma/ii,  or  any  other  term  signifying  earth  ;  the  ground  or  base  of  a  triangle  or 
other  plane  figure.  Any  one  of  the  sides  is  taken  for  the  base  ;  and  the  rest  are  termed  simply^ 
sidcs»    Gan'e's'a  restricts  the  term  to  the  greatest  side.     See  note  §  l68. 

Lamia,  &c.  the  perpendicular.     See  note  on  §.  159. 


70  XT L A' V ATT.  Chapter  VI. 

is  subtracted  from,  and  added  to,  the  base  which  is  twice  set  down :  and 
being  halved,  the  results  are  segments  corresponding  to  those  sides. "^ 

164.  The  square-root  of  the  difference  of  squares  of  the  side  and  its  own 
segment  of  the  base  becomes  the  perpendicular.  Half  the  base,  multiplied 
by  the  perpendicular,"  is  in  a  triangle  the  exact'  area.* 

Ab^d'lid,  abad'hi,  avabad'M,  segment  of  the  base.  These  are  terms  introduced  by  earlier  writers. 
From  the  point,  where  a  perpendicular  falling  from  the  ape.\  (mastaca)  meets  the  base,  the  two 
portions  or  divisions  of  the  ground  on  their  respective  sides  [or,  if  the  perpendicular  fall  without  the 
figure  in  an  obtuse-angled  one,  on  the  same  side]  are  distinguished  by  this  name. 

Phala,  Gatiita,  Cshetra-phala,  Sama-coshia-ntili;  the  measure  of  like  compartments,  or  number 
of  equal  squares  of  the  same  denomination  (as  cubit,  fathom,  finger,  &c.)  in  which  the  dimension 
of  the  side  is  given  :  the  area  or  superficial  content.  It  is  the  product  of  multiplication  of  length 
by  breadth.  Gan.  and  Sua. 

*  The  relative,  dependent,  or  corresponding  segments.  The  smaller  segment  answers  to  the  less 
side;  the  larger  segment  to  the  greater  side.  Gan. 

*  Or  half  the  perpendicular  taken  into  the  base.  Gan. 

'  Sphuta-phala  distinct  or  precise  area ;  opposed  to  asphuta — or  si'hula-phala  iadistiact  or  gross 
area.     See  §  l67 — and  Arithm.  of  Braiim.  §  21. 

*  Demonstration :  In  both  the  right-angled  triangles  formed  in  the  proposed  triangular  figure, 
one  on  each  side  of  the  perpendicular,  this  line  is  the  upright ;  the  side  is  hypotenuse,  and  the 
correspondent  segment  is  side.  Hence,  subtracting  the  square  of  the  perpendicular  from  the  square 
of  the  side,  the  remainder  is  square  of  the  segment.  So,  subtracting  the  square  of  the  other  side, 
there  remains  the  square  of  the  segment  answering  to  it.  Their  difference  is  the  difference  of  the 
squares  of  the  segments  and  is  equal  to  the  difference  of  the  squares  of  the  sides  ;  since  an  equal 
quantity  has  been  taken  from  each  :  for  any  two  quantities,  less  an  equal  quantity,  have  the  same 
difference.  It  is  equal  to  the  product  of  the  sum  and  difference  of  the  simple  quantities.  There- 
fore th'S  sum  of  the  sides,  multiplied  by  their  difference,  is  the  difference  of  the  squares  of  the 
segments.  But  the  base  is  the  sura  of  the  segments.  The  difference  of  the  squares,  divided  by 
that,  is  the  difference  of  the  segments.  From  which,  by  the  rule  of  concurrence  (,§  55)  the  seg- 
ments are  found. 

The  square-root  of  the  difference  between  the  squares  of  the  side  and  segment  (taken  as  hypote- 
nuse and  side)  is  the  upright.     It  is  the  perpendicular. 

Dividing  the  triangle  by  a  line  across  the  middle,  and  placing  the  two  halves  [or  parts]  of  the 
upper  portion  disjoined  by  the  perpendiculur,  on  the  two  sides  of  the  lower  portion,  an  oblong  is  form- 
ed ;  inwhich  the  halfof  the  perpendicular  is  one  side,  and  the  base  is  the  other.  See 
Wherefore  half  the  perpendicular,  multiplied  by  the  base,  is  the  area  or  num- 
ber of  equal  compartments.  Or  half  the  base,  multiplied  by  the  pcrpendicu-  6\ 
lar,  is  just  so  much. — Gax. 

If  with  the  sum  of  the  sides,  this  difference  be  had,  then  with  this  sura  of  the  segments,  that  is. 


PLANE   FIGURE,  71 

165.  Example.  In  a  triangular  figure,  in  which  the  base  is  fourteen  and 
its  sides  thirteen  and  fifteen,  tell  quickly  the  length  of  the  perpendicular, 
the  segments,  and  the  dimensions  by  like  compartments  termed  area. 

Statement:  Base  14.  Sides  13  and  15.  Proceeding  as  directed,  the  seg- 
ments are  found,  5  and  9  ',  and  the  perpendicular,  la  :  the  area,  84.     See 


166.  Example.  In  a  triangle,  wherein  the  sides  measure  ten  and  seven- 
teen, and  the  base  nine,  tell  me  promptly,  expert  mathematician,  the  seg- 
ments, perpendicular  and  area. 

Statement:  Sides  10  and  17.  Base  9-  By  the  rule  §  163,  the  quotient 
found  is  21.  This  cannot  be  subtracted  from  the  base.  Wherefore  the  base 
is  subtracted  from  it.  Half  the  remainder  is  the  segment,  6 ;  and  is  nega- 
tive :  that  is  to  say,  is  in  the  contrary  direction.*     Thus  the  two  segments 

with  the  base  which  is  their  sum,  what  is  obtained  ?  Here,  as  the  demand  increases,  the  fruit 
decreases:  wherefore,  by  the  inverse  rule  of  three  §74',  the  difference  of  the  sides,  multiplied  by 
their  sum,  and  divided  by  the  base,  gives  the  difference  of  the  segments.  With  that  and  the  base, 
which  is  their  sum,  the  segments  are  found  by  the  rule  of  concurrence  §  55. 

In  an  acute-angled  triangle,  two  right-angled  triangles  are  formed  by  the  perpendicular  within 
it.  The  side  becomes  an  hypotenuse,  the  segment  a  side,  and  the  unknown  perpendicular  an  up- 
right alike  in  both.  Hence  (§  134)  the  square-root  of  the  difference  of  the  squares  of  the  side  and 
segment  is  the  perpendicular. 

The  perpendicular  is  the  breadth ;  and  the  base  is  the  length.  It  is  exactly  so  in  the  lower 
part;  but  not  so  in  the  upper  part:  for  there  the  figure  terminates  in  a  sharp  point.  Wherefore 
half  the  length  is  the  length  to  be  multiplied.  If  two  triangles  be  placed  within  a  quadrilateral,  it 
is  readily  perceived,  that  the  triangle  is  half  the  quadrilateral.  Or  if  an  acute-angled  triangle  be 
figured,  two  right-angled  triangles  are  formed  by  the  perpendicular;  and  their  bases  are  the  seg- 
ments. The  moieties  of  the  segments,  multiplied  by  the  perpendicular,  are  the  areas  of  the  two 
rectangular  triangles.     Their  sum  is  the  area  of  the  proposed  triangle. — Sun. 

In  an  obtuse-angled  triangle  also,  the  base  multiplied  by  half  the  perpendicular  is  the  area. 

Gan. 

'  When  the  perpendicular  falls  without  the  base,  as  overpassing  the  angle  in  consequence  of 
the  side  exceeding  the  base,  the  quotient  found  by  the  rule  §  10'3  cannot  be  taken  from  the  base  : 
for  both  origins  of  sides  are  situated  in  the  same  quarter  from  the  fall  of  the  perpendicular.  There- 


72  LI' LAV  ATI'.  Chapter  VL 

are  found  6  and  15.     From  which,  both  ways  too,  the  perpendicular  comes 
out  8.     The  area,    36.     See 

10\  "\J7 


167.  Rule.^  Half  the  sum  of  all  the  sides  is  set  down  in  four  places; 
and  the  sides  are  severally  subtracted.  The  remainders  being  multiplied  to- 
gether, the  square-root  of  the  product  is  the  area,  inexact  in  the  quadrila- 
teral, but  pronounced  exact  in  the  triangle." 

168.  Example.  In  a  quadrilateral  figure,  of  which  the  base'  is  fourteen, 
the  summit*  nine,  the  flanks  thirteen  and  twelve,  and  the  perpendicular 
twelve,  tell  the  area  as  it  was  taught  by  the  ancients. 

fore  subtracting  the  base  from  the  quotient,  half  the  residue  is  the  segment  and  situated  on  the 
contrary  side,  bein"  negative.  Wherefore,  as  both  segments  stand  on  the  same  side,  the  smaller 
is  comprehended  in  the  greater ;  and,  in  respect  of  it,  is  negative.  Thus  all  is  congruous  and  un- 
exceptionable.— Gan.  When  the  sum  of  the  segments  is  to  be  taken,  as  they  have  contrary 
signs,  affirmative  and  negative,  the  difference  of  the  quantities  is  that  sum. — Sur.     See  Vij.-gan. 

§5. 

•  For  finding  the  gross  area  of  a  quadrilateral ;  and,  by  extension  of  the  rule,  the  exact  area  of 
a  triangle.— Gan.  For  finding  the  area  by  a  method  delivered  by  Sbid'haua,  as  a  general  one 
common  to  all  figures.— Rang.  Excepting  an  equidiagonal  quadrilateral.— Cffum.  Sri'd'hara's 
rule,  which  is  here  censured,  occurs  in  his  compendium  of  Arithmetic. — Gaii.  sir.  §  126.  See 
likewise  Arithm.  of  Brahmegupta,  §21. 

»  In  the  case  of  a  triangle,  half  the  sum  of  the  three  sides  is  four  times  set  down;  the  three 
sides  are  subtracted  severally  in  three  instances  :  in  the  fourth,  it  remains  unchanged.  The  square- 
root  of  the  product  of  such  four  quantities  is  the  exact  area. — Gan. 

If  the  three  remainders  be  added  together,  their  sum  is  equal  to  half  the  sum  of  all  the  sides. 
The  product  of  the  continual  multiplication  of  the  three  remainders  being  taken  into  the  sum  of 
those  remainders,  the  product  so  obtained  is  equal  to  the  product  of  the  square  of  the  perpendi- 
cular taken  into  the  square  of  half  the  base.  It  is  a  square  quantity  :  for  a  square,  multiplied  by 
a  square,  gives  a  square.  The  square-root  being  extracted,  the  product  of  the  perpendicular  by 
half  the  base  is  the  result :  and  that  is  the  area  of  the  trikngle.  Therefore  the  true  area  is  thus 
found.  In  a  quadrilateral,  the  product  of  the  multiplication  does  not  give  a  square  quantity  :  but 
'  an  irrational  one.  Its  approximate  root  is  the  area  of  the  figure  ;  not,  however,  the  true  one  :  for, 
when  divided  by  the  perpendicular,  it  should  give  half  the  sum  of  the  base  and  summit.— Sur. 

»  The  greatest  of  the  four  sides  is  called  the  base.— Gan.  This  definition  is,  however,  too  re- 
stricted. See  §  185  and  178.  The  notion  of  it  is  taken  from  Brahmegupta.  Arithm. 
§38. 

*  Muc'/ia,  vadana,  or  other  terra  expressing  mouth  :  the  side  opposite  to  the  base ;  the  summit. 


PLANE    FIGURE. 
Statement:  Base  14.  Summit  9.    Sides  13 and  12.    Perp.  12. 


14 


By  the  method  directed,  the  result  obtained  is  the  surd  19800,  of  which 
the  approximated  root  is  somewhat  less  than  a  hundred  and  forty -one  :  141. 
That,  however,  is  not  in  this  figure  the  true  area.  But,  found  by  tlie  me- 
thod which  will  be  set  forth  (§  175),  the  true  area  is  138. 


Statement  of  the  triangle  before  instanced       ,,  / 

By  this  method  the  area  comes  out  the  same :  viz.  84. 

169 — 170.  Aphorism  comprised  in  a  stanza  and  a  half:  Since  the  diago- 
nals of  the  quadrilateral  are  indeterminate,  how  should  the  area  be  in  this 
case  determinate  ?  The  diagonals,  found  as  assumed  by  the  ancients,'  do 
not  answer  in  another  case.  With  the  same  sides,  there  are  other  diagonals  ; 
and  the  area  of  the  figure  is  accordingly  manifold. 

For,  in  a  quadrilateral,  opposite  angles,  being  made  to  approach,  contract 
their  diagonal  as  they  advance  inwards :  while  the  other  angles,  receding 
outwards,  lengthen  their  diagonal.  Therefore  it  is  said,  "  with  the  same 
sides,  there  are  other  diagonals." 

171.  How  can  a  person,  neither  specifying  one  of  the  perpendiculars,  nor 
cither  of  the  diagonals,  ask  the  rest?''  or  how  can  he  demand  a  determinate 
area,  while  they  are  indefinite  ? 

172.  Such  a  questioner  is  a  blundering  devil.'  Still  more  so  is  he,  who 
answers  the  question.  For  he  considers  not  the  indefinite  nature  of  the 
lines*  in  a  quadrilateral  figure. 

*  By  Srio'hara  and  tbe  rest.  Gan. 

*  The  perpendiculars,  diagonals,  &c.  Gan. 
'  Pis&cha  (a  demon  or  vampire).     So  termed,  because  he  blunders.                                  Su'r. 

*  Of  the  diagonal  and  perpendicular  lines.  Sun. 


74 


LI' LA' V  ATI'. 


Chapter  VI. 


173 — 175.  Rule*  in  two  and  a  half  stanzas  :  Let  one  diagonal  of  an  equi- 
lateral tetragon  be  put  as  it  is  given.  Then  subtract  its  square  from  four 
times  the  stjuare  of  the  side.  The  square-root  of  the  remainder  is  the  measure 
of  the  second  diagonal. 

174.  The  product  of  unequal  diagonals  multiplied  together,  being  di- 
vided by  two,  will  be  the  precise  area  in  an  equilateral  tetragon.  But  in  a 
regular  one  with  equal  diagonals,  as  also  in  an  oblong,*  the  product  of  the 
side  and  upright  will  be  so. 

175.  In  any  other  quadrilateral  with  equal  perpendiculars,*  the  moiety 
of  the  sum  of  the  base  and  summit,  multiplied  by  the  perpendicular,  [is  the 
area.] 

176.  Mathematician,  tell  both  diagonals  and  the  area  of  an  equilateral 
quadrangular  figure,  whose  side  is  the  square  of  five :  and  the  area  of  it,  the 
diagonals  being  equal:  also  [the  area]  of  an  oblong,  the  breadth  of  which 
is  six  and  the  length  eight. 


Statement  of  first  figure      25 


Here,  taking  the  square-root  of 


the  sum  of  the  squares  (§  134),  the  diagonal  comes  out  the  surd  1250,  alike 
both  ways.     The  area  625. 

Assume  one  diagonal  thirty ;  the  other  is  found  40 ;  and  the  area  6OO.    See 


Put  one  diagonal  fourteen :  the  other  is  found  48 ;  and  area  336.     See 


'  In  an  equilateral  tetragon,  one  diagonal  being  given,  to  find  the  second  diagonal  and  the  area: 
also  in  an  equi-perpendicular  tetragon  [trapezoid]  to  find  the  area. — Gan.  Equilateral  tetragons 
are  twofold  :  with  equal,  and  with  unequal,  diagonals.  The  first  rule  regards  the  equilateral  te- 
tragon with  unequal  diagonals  [the  rhomb.]  Su'r. 

*  Ayata:  a  long  quadrilateral  which  has  pairs  of  equal  sides.  Gan. 

*  In  an  unequal  quadrilateral  figure,  to  find  the  area. — SuR.  In  any  quadrilateral  with  two, 
or  with  three,  equal  sides,  or  with  all  unequal,  but  having  equal  perpendiculars.  Rang. 


Statement  of  the  oblong 


PLANE    FIGURE.  73. 

Area  48. 


I 


177.  Example.  Where  the  summit  is  eleven;  the  base  twice  as  much 
as  the  summit;  and  the  flanks  thirteen  and  twenty;  and  the  perpendicular 
twelve ;  say  what  will  be  the  area  ? 

11 

\         i\.  The  gross  area  (i  167)  is  250.      The  true 

Statement:    13\    12!    \20  /-:,«/-%•     ,,L 

\       i        \r       area  (^  175)  is  I98. 

22 

Or  making  three  portions  of  the  figure,  and  severally  finding  their  areas, 

and  summing  them,  the  principle  may  be  shown.  ^  ^^ 

13V  ■     loi       \20 


178.  Example.  Declare  the  diagonal,  perpendicular  and  dimensions  of 
the  area,  in  a  figure  of  which  the  summit  is  fifty-one,  the  base  seventy-five, 
the  left  side  sixty-eight,  and  the  other  side  twice  twenty. 

179.  Aphorism  showing  the  connexion  of  area,  perpendicular  and  dia- 
gonal : 

If  the  perpendicular  be  known,  the  diagonal  is  so:  if  the  diagonal  be 
known,  the  perpendicular  is  so :  if  they  be  definite,  the  area  is  determinate. 

For,  if  the  diagonal  be  indefinite,  so  is  the  perpendicular.  Such  is  the 
meaning. 

179  continued.  Rule  for  finding  the  perpendicular:'  In  the  triangle 
within  the  quadrilateral,  the  perpendicular  is  found  as  before  taught  :^  the 
diagonal  and  side  being  sides,  and  the  base  a  base.' 

Here,  to  find  the  perpendicular,  a  diagonal,  proceeding  from  the  extre- 


'  The  diagonal  being  either  given  or  assumed.  Gan. 

»  See§  163  and  l64. 

*  The  summit  becomes  base  of  the  second  triangle;  the  diagonal  is  one  leg;  and  the  remaining 
side  of  the  quadrilateral,  the  other.  Rang. 


76 


LI'LAVATI'. 


Chapter  VI. 


mity  of  the  left  side  to  the  origin  of  the  right  one,  is  assumed,  put  at 
seventy-seven.     See 


By  this  a  triangle  is  constituted  within  the  quadrilateral.  In  it  that  dia- 
gonal is  one  side,  77 ;  the  left  side  is  another,  68  ;  the  base  continues  such, 
75.  Then,  proceeding  by  the  rule  (§  163  —  164),  the  segments  are  found  —■ 
and  ^^•,  and  the  perpendicular. 


308 
3     ■ 


See  figure. 


180.     Rule  to  find  the  diagonal,  when  the  perpendicular  is  known : 
The  square-root  of  the  difference  of  the  squares  of  the  perpendicular  and 
its  adjoining  side  is  pronounced  the  segment.     The  square  of  the  base  less 
that  segment  being  added  to  the  square  of  the  perpendicular,  the  square- 
root  of  the  sum  is  the  diagonal. 

In  that  quadrilateral,  the  perpendicular  from  the  extremity  of  the  left 
side  is  put  ^.  Hence  the  segment  is  found  ^-~  ;  and  by  the  rule  (§  180) 
the  diagonal  comes  out  77- 

181  — 182.  Rule  to  find  the  second  diagonal  [two  stanzas]  : 
In  this  figure,  first  a  diagonal  is  assumed.'  In  the  two  triangles  situated 
one  on  either  side  of  the  diagonal,  this  diagonal  is  made  the  base  of  each  ; 
and  the  other  sides  are  given :  the  perpendiculars  and  segments^  must  be 
found.  Then  the  square  of  the  difference  of  two  segments  on  the  same 
side'  being  added  to  the  square  of  the  sum  of  the  perpendiculars,  the  square- 
root  of  the  sum  of  those  squares  will  be  the  second  diagonal  in  all  tetragons.* 
In  the  same  quadrilateral,  the  length  of  the  diagonal  passing  from  the 
extremity  of  the  left  side  to  the  origin  of  the  right  one,  is  put  77.  Within 
the  figure  cut  by  that  diagonal  line,  two  triangles  are  formed,  one  on  each 


'  Either  arbitrarily  [see  §  183]  or  as  given  by  the  conditions  of  the  question.  Gan". 

^  The  two  perpendiculars  and  the  four  segments.  Gang. 

3  Square  of  the  interval  of  two  segments  measured  from  the  same  extremity. 

*  In  the  figure,  which  is  divided  by  the  diagonal  line,  two  triangles  are  contained  :  one  on  each 
side  of  that  line;  and  their  perpendiculars,  which  fall  one  on  each  side  of  the  diagonal, are  thence 
found.  The  ditference  between  two  segments  on  the  same  side  will  be  the  interval  between  the 
perpemlicula]^.     It  is  taken  as  the  upright  of  a  triangle.     Producing  one  perpendicular  by  the  ad- 


PLANE    FIGURE. 


n 


side  of  the  diagonal.  Taking  the  diagonal  for  the  base  of  each,  and  the  two 
other  sides  as  given,  the  two  perpendiculars  and  the  several  segments  must 
be  found  by  the  method  beibre  taught.     See  figure 


viz.  Perpendiculars  24  and  60.  Segment  of  the  base  of  the  one  part  45 
and  32  ;  of  the  other  32  and  45.  Difference  of  the  segments  on  the  same 
side  (that  is,  so  much  of  the  base  as  is  intercepted  between  the  perpendicu- 
lars) 13.  Its  square  I69.  Sum  of  the  perpendiculars  84.  Its  square  7056. 
Sum  of  the  squares  7225.     Square-root  of  the  sum  85.     It  is  the  length  of 


the  second  diagonal. 


So  in  every  like  instance. 


183 — 184.  Rule  restricting  the  arbitrary  assumption  of  a  diagonal  [a 
stanza  and  a  half:]  The  sum  of  the  shortest  pair  of  sides  containing  the  dia- 
gonal being  taken  as  a  base,  and  the  remaining  two  as  the  legs  [of  a  triangle,] 
the  perpendicular  is  to  be  found:  and,  in  like  manner,  with  the  other  diagonal. 
The  diagonal  cannot  by  any  means  be  longer  than  the  corresponding  base, 
nor  shorter  than  the  perpendicular  answering  to  the  other.  Adverting  to 
these  limits  an  intelligent  person  may  assume  a  diagonal. 

For  a  quadrilateral,  contracting  as  the  opposite  angles  approach,  becomes 
a  triangle  ;  wherein  the  sum  of  the  least  pair  of  sides  about  one  angle  is  the 


diiion  of  the  other,  the  sum  is  made  the  side  of  the  triangle.    The  second  diagonal  is  hypotenuse. 
A  triangle  is  thus  formed.     See 


From  this  is  deduced,  that  the  square-root  of  the  sum  of  the  squares  of  the  upright  and  side 
will  be  the  second  diagonal :  and  the  rule  is  demonstrated.  Gan. 

In  an  equilateral  tetragon,  and  in  a  trapezium  of  which  the  greatest  side  is  the  base  and  the  least 
is  the  summit,  there  is  no  interval  between  the  perpendiculars;  and  the  second  diagonal  is  the 
sura  of  the  perpendiculars.  Ibid. 


78  LI'LAVATI'.  Chapter  VI. 

base ;  and  the  other  two  are  taken  as  the  legs.  The  perpendicular  is  found 
in  the  manner  before  taught.  Hence  the  shrinking  diagonal  cannot  by  any 
means  be  less  than  the  perpendicular ;  nor  the  other  be  greater  than  the  base. 
It  is  so  both  ways.  This,  even  though  it  were  not  mentioned,  would  be 
readily  perceived  by  the  intelligent  student. 

184.  Rule  to  fiiid  the  area  [half  a  stanza :]  The  sum  of  the  areas  of  the 
two  triangles  on  either  side  of  the  diagonal  is  assuredly'  the  area  in  this 
figure. 

In  the  figure  last  specified,  the  areas  of  the  two  triangles  are  924  and 
2310.     The  sum  of  which  is  3234;  the  area  of  the  tetragon. 

185 — 186.  Rule''  [two  stanzas:]  Making  the  difference  between  the 
base  and  summit  of  a  [trapezoid,  or]  quadrilateral  that  has  equal  perpendicu- 
lars, the  base  [of  a  triangle],  and  the  sides  [its]  legs,  the  segments  of  it  and 
the  length  of  the  perpendicular  are  to  be  found  as  for  a  triangle.  From  the 
base  of  the  trapezoid  subtracting  the  segment ;  and  adding  the  square  of  the 
remainder  to  the  square  of  the  perpendicular,  the  square-root  of  the  sum  will 
be  the  diagonal.' 

In  a  [trapezoid,  or]  quadrangle  that  has  equal  perpendiculars,  the  sum  of 
the  base  and  least  flank  is  greater  than  the  aggregate  of  the  summit  and 
other  flank. 


'  It  is  the  true  and  correct  area,  contrasted  with  the  gross  or  inexact  area  of  former  writers. 

Gajj'.  and  SuR. 

*  To  find  definite  diagonals,  when  neither  is  given;  nor  the  perpendicular ;  but  the  condition 
that  the  perpendiculars  be  equal ;  which  is  a  suflRcient  limitation  of  the  problem. 

^  In  a  quadrilateral  figure  having  equal  perpendiculars,  the  intermediate  portion  between  the 
extreme  perpendiculars  being  taken  away,  there  remain  two  rectangular  triangles  on  the  outer 
side.  Uniting  them  together,  a  triangle  is  formed,  in  which  the  flanks  are  legs,  and  the  base  less 
the  summit  is  the  base.  Hence  the  perpendicular  in  this  triangle,  found  by  the  rule  before  taught 
(§  164.),  is  precisely  the  perpendicular  of  the  tetragon;  and  the  segments,  which  are  found  (§  l63), 
lie  between  the  perpendicular  and  the  corresponding  sides.  The  base  of  the  tetragon,  less  either 
of  the  segments,  is  the  side  of  a  rectangular  triangle  within  the  same  tetragon ;  and  the  perpen- 
dicular is  its  upright :  wherefore  the  square-root  of  the  sum  of  their  squares  is  the  correspondent 
diagonal :  and,  in  like  manner,  with  the  other  segment,  the  diagonal  resting  on  the  other  perpen- 
dicular is  found.  '  Gan. 


PLANE    FIGURE. 


79 


187 — 189-  The  sides  measuring  fifty-two  and  one  less  than  forty  ;  the 
summit  equal  to  twenty-five,  and  the  base  sixty :  this  was  given  as  an  ex- 
ample by  former  writers  for  a  figure  having  unequal  perpendiculars ;  and 
definite  measures  of  the  diagonals  were  stated,  fifty-six  and  sixty-three. 
Assign  to  it  other  diagonals ;  and  those  particularly  which  appertain  to  it  as 
a  figure  with  equal  perpendiculars. 


Statement : 


Here  assuming  one  diagonal  sixty-three,  63,  the  other  is  found  as  before, 
56.  Or,  putting  thirty-two  instead  of  fifty-six  for  a  diagonal,  the  other,  found 
by  the  process  before  shown,  comes  out  in  two  portions,  both  surds,  621  and 
2700.  The  sum  of  the  roots  [as  extracted  by  approximation]  is  the 
second  diagonal  76  ^.  See  figure  of  a  triangle  put  to  find  the  perpendi- 
cular : 


Here  the  segments  are  found  f  and  i^  j  and  the  perpendicular,  the  surd 
;  of  which  the  root  found  by  approximation  is  38f|f .  It  is  the  equal 
perpendicular  of  that  tetragon. 

Next  the  sum  of  the  squares  of  the  perpendicular  and  difference  between 
base  and  segment :  Base  of  the  tetragon,  60 :  least  segment  f ;  diflfereuce 
^.  Square  of  the  difference  a^^.  Square  of  the  perpendicular,  which 
was  a  surd  root,  ^■^^.  Sum  i^||i^  ;  or,  dividing  by  the  denominator,  5049- 
It  is  the  square  of  one  diagonal.  So  base  60 ;  greater  segment  '--^  ;  difi'er- 
ence  4^.  Its  square  •-^.  Square  of  the  surd  perpendicular  '-^. 
Sum  ~^;  or,  dividing  by  the  denominator,  2176.  It  is  the  sum  of  the 
squares  of  the  perpendicular  and  difference  between  base  and  greater  seg- 


38016 

23 


80 


LI'LAVATr. 


Chapter  VI. 


inent;  and  is  the  square  of  the  second  diagonal.     Extracting  the  roots  of 
these  squares  by  approximation,  the  two  diagonals  come  out  71  -jV  and  46  -*^. 

25 

See 


w\         / 

\ 

CO    ^\/ 

X,^ 

39' 

\5? 

J 

25 

34f\ 

60 


In  this  tetragon  with  equal  perpendiculars  the  short  side  39  added  to  the 
base  60,  makes  99 :  which  is  greater  than  the  aggregate  of  the  summit  and 
other  flank,  77.     Such  is  the  limitation. 

Thus,  with  the  same  sides,  may  be  many  various  diagonals  in  the  tetra- 
gon. Yet  though  indeterminate,  diagonals  have  been  sought  as  determinate, 
by  Brahmegupta  and  others.     Their  rule  is  as  follows. 

190.  Rule:'  The  sums  of  the  products  of  the  sides  about  both  the  dia- 
gonals being  divided  by  each  other,  multiply  the  quotients  by  the  sum  of 
the  products  of  opposite  sides ;  the  square-roots  of  the  results  are  the  dia- 
gonals in  a  trapezium. 

The  objection  to  this  mode  of  finding  the  diagonals  is  its  operoseness,  as 
I  shall  show  by  proposing  a  shorter  method. 

191 — 192.  Rule  [two  stanzas] :  The  uprights  and  sides  of  two  assumed 
rectangular  triangles,"  being  multiplied  by  the  reciprocal  hypotenuses,  be- 
come sides  [of  a  quadrilateral] :  and  in  this  manner  is  constituted  a  trape- 
zium, in  which  the  diagonals  are  deducible  from  the  two  triangles.'  The 
product  of  the  uprights,  added  to  the  product  of  the  sides,  is  one  diagonal ; 
the  sum  of  the  products  of  uprights  and  sides  reciprocally  multiplied,  is  the 


"  A  couplet  cited  from  Brahmegupta.     12.  §  28. 

*  Assumed  conformably  with  the  rule  contained  in  §  145.  An  objection,  to  which  the  cora- 
roentator  Gan'e's'a  adverts,  and  which  he  endeavours  to  obviate,  is  that  this  shorter  method  re- 
quires sagacity  in  the  selection  of  assumed  triangles;  and  that  the  longer  method  is  adapted  to  all 
capacities. 

*  This  method  of  constructing  a  trapezium  is  taken  from  Brahmegupta.     12.  §  38. 


PLANE    FIGURE. 


81 


other.'     When  this  short  method  presented,  why  an  operose  one  was  prac- 
tised by  former  writers,  we  know  not." 

'  A  trapezium  is  divided  into  four  triangles  by  its  intersecting  diagonals ;  and  conversely,  by 
the  junction  of  four  triangles,  a  trapezium  is  constituted.  For  that  purpose,  four  triangles  are 
assumed  in  this  manner.  Two  triangles  are  first  put  in  the  mode  directed  (§  145),  the  sides  of 
which  are  all  rational.  Such  sides,  multiplied  by  any  assumed  number,  will  constitute  other  rect- 
angular triangles,  of  which  also  the  sides  will  be  rational.  By  the  twofold  multiplication  of  h}'- 
potenuse,  upright  and  side  of  one  assumed  triangle  by  the  upright  and  side  of  the  other,  four  tri- 
angles are  formed,  such  that  turning  and  adapting  them  and  placing  the  multiples  of  the  hypote- 
nuses for  sides,  this  trapezium  is  composed. 

25 


4^5 

3  5  15  20  15  36  60 

Here  the  uprights  and  sides  of  the  arbitrary  triangles,  reciprocally  multiplied  by  the  hypotenuses, 
become  sides  of  the  quadrilateral:  and  hence  the  directions  of  the  rule  (§  191).  ' 

In  a  trapezium  so  constituted,  it  is  apparent,  that  the  one  diagonal  is  composed  of  two  parts ; 
one  the  product  of  the  uprights,  the  other  the  product  of  the  sides  of  the  arbitrary  triangles.  The 
other  diagonal  consists  of  two  parts,  the  products  of  the  reciprocal  multiplication  of  uprights  and 
sides.  These  two  portions  are  the  perpendiculars:  for  there  is  no  interval  between  the  points  of 
intersection.  This  holds,  provided  the  shortest  side  be  the  summit ;  the  longest,  the  base  ;  and  the 
rest,  the  flanks.  But,  if  the  component  triangles  be  otherwise  adapted,  the  summit  and  a  flank 
change  places.     See 

.39 


Here  the  two  portions  of  the  first  diagonal,  as  above  found  (viz.  48  and  13)  do  not  face ;  but  are 
separated  by  an  interval,  which  is  equal  to  the  diflerence  between  the  two  portions  of  the  other  dia- 
gonal (36  and  20)  viz.  l6.  It  is  the  difference  of  two  segments  on  the  same  side,  found  by  a  pre- 
ceding rule  (§181—182);  and  is  the  interval  between  the  intersections  of  the  perpendiculars;  and 
is  taken  for  the  upright  of  a  triangle,  as  already  explained  (§  181,  note)  :  the  sum  of  the  two  por- 
tions of  diagonal  equal  to  the  two  perpendiculars  is  made  the  side.  The  square-root  of  the  sura  of 
the  squares  of  such  upright  and  side  is  equal  to  the  product  of  the  hypotenuses  (13  and  5):  where- 
fore the  author  adds  "  if  the  summit  and  flank  change  places,  the  first*  diagonal  will  be  the  pro- 
duct of  the  hypotenuses." 

From  the  demonstration  of  Brahmegxjpta's  rule  (Arithm.  of  Braum.  §  28)  may  be  deduced 

•  So  Ibe  MSS.     But  BniscAttA's  teit  exhibits  second. 
M 


8S 


LI'LA'VATI'. 


Chapter  VI. 


Assuming  two  rectangular  triangles,    *{X  ^^  A       Multiply  the   upright 

3         5 

and  side  of  one  by  the  hypotenuse  of  the  other :  the  greatest  of  the  pro<lucts 

is  taken  for  the  base ;  the  least  for  the  summit ;  and  the  other  two  for  the 

flanks.      See  ^^3^ 

I    ^''^ 
39/     /V       \52 


Here,  with  much  labor  [by  the  former  method]  the  diagonals  are  found 
63  and  SQ. 

With  the  same  pair  of  rectangular  triangles,  the  products  of  uprights  and 
sides  reciprocally  multiplied  are  36  and  20  :  the  sum  of  which  is  one  dia- 


grounds  of  a  succinct  proof,  that  the  diagonal  is  found  by  multiplication  of  the  hj'potenuses,  when 
the  summit  is  not  the  least  side.  For,  if  the  two  derivative  triangles  be  fitted  together  by  bringing 
the  hypotenuses  in  contact,  the  trapezium  is  such  as  is  produced  by  the  transposition  of  the  sura* 
mit  and  a  flank,  and  the  diagonal  is  the  product  of  the  hypotenuses  of  the  generating  triangles. 
<Jah'.  48  15 


20 


36 


^J^'"^ 

\39 

\\ 

/jb 

36 
20 


60  48  15 

»  In  like  manner,  for  the  tetragon  before  instanced  (§  178),  to  find  the  diagonals,  a  pair  of  rec- 


tangular triangles  is  put 


4^^ 


15 


\1'     Proceeding  as  directed,  the  diagonals  come  out  77  and 


3  3 

84.     In  the  figure  instanced,  a  transposition  of  the  flank  and  summit  takes  place 

_40 


75  75 

wherefore  the  product  of  the  hypotenuse  of  the  two  rectangular  triangles  will  be  the  second  dia- 
gonal :  and  they  thus  come  out  "Jt  and  85.  Gan. 


PLANE    FIGURE. 


8S 


gonal,  56.  The  products  of  uprights  multiplied  together,  and  sides  taken 
into  each  other,  are  48  and  15  :  their  sum  is  the  other  diagonal,  63.  Thus 
they  are  found  with  ease. 

■'  But  if  the  summit  and  flank  change  places,  and  the  figure  be  stated  ac- 
cordingly, the  second  diagonal  will  be  the  product  of  the  hypotenuses  of  the 
two  rectangular  triangles  :  viz.  65.     See 


193 — 194.  Example.*  In  a  figure,  in  which  the  base  is  three  hundred, 
the  summit  a  hundred  and  twenty-five,  the  flanks  two  hundred  and  sixty 
and  one  hundred  and  ninety-five,  one  diagonal  two  hundred  and  eighty  and 
the  other  three  hundred  and  fifteen,  and  the  perpendiculars  a  hundred  and 
eighty-nine  and  two  hundred  and  twenty -four ;  what  are  the  portions  of  the 
perpendiculars  and  diagonals  below  the  intersections  of  them?  and  the  per- 
pendicular let  fall  from  the  intersection  of  the  diagonals  ;  with  the  segments 
answering  to  it  ?  and  the  perpendicular  of  the  needle  formed  by  the  pro- 
longation of  the  flanks  until  they  meet  ?  as  well  as  the  segments  correspond- 
ing to  it ;  and  the  measure  of  both  the  needle's  sides  ?  All  this  declare,  ma- 
thematician, if  thou  be  thoroughly  skilled  in  this  [science  of]''  plane  figure. 


Statement ; 


:V2S-^ 


195; 


Length  of  the  base  300.  Summit  1 25. 
Flanks  260  and  195.  Diagonals  280 
and   315.      Perpendiculars    189  and 

224r. 


ff>48S'    300  j;    132 


^-48^ 


•  Having  thus,  from  §  173  to  this  place,  shown  the  method  of  finding  the  area,  &c.  in  the  four- 
teen sorti  of  quadrilaterals,  the  author  now  exhibits  another  trapezium,  proposing  questions  con- 
cerning segments  produced  by  intersections. — Gan.  The  author  proposes  a  question  in  the  form 
of  an  example. — Gang.  For  the  instruction  of  the  pupil,  he  exhibits  the  figure  called  (suchi)  a 
needle.     Manor. 

The  problem  is  taken  from  Brahmegupta  with  a  slight  variation;  and  this  example  differs 
from  his  only  in  the  scale,  his  numbers  being  here  reduced  to  fifths.    Arithm.  of  Brahm.  §  32. 

*  Manorunjana. 

m2 


84  LI'LAVATI'.  Chapter  VI. 

195 — 196.  Rule  (two  stanzas):  The  interval  between  the  perpendicular 
and  its  correspondent  flank  is  termed  the  sand'hi'  or  link  of  that  perpendicu- 
lar. The  base,  less  the  link  or  segment,  is  called  the  pii'ha  or  complement  of 
the  same.  The  link  or  segment  contiguous  to  that  portion  [of  perpendicular 
or  diagonal]  which  is  sought,  is  twice  set  down.  Multiplied  by  the  other 
perpendicular  in  one  instance,  and  by  the  diagonal  in  the  other,  and  divided 
[in  both  instances]  by  the  complement  belonging  to  the  other  [perpendicu- 
lar], the  quotients  will  be  the  lower  portions  of  the  perpendicular  and  dia- 
gonal below  the  intersection. 

Statement:  Perpendicular  189.  Flank  contiguous  to  it  195.  Segment 
intercepted  between  them  (found  by  §  134)  48.  It  is  the  link.  The  second 
segment  (found  by  §  195)  is  2.52,  and  is  called  the  complement. 

In  like  manner  the  second  perpendicular  224.  The  flank  contiguous  to 
it  260.  Interval  between  them,  being  the  segment  called  link,  132.  Com- 
plement 168. 

Now  to  find  the  lower  portion  of  the  first  perpendicular  189.  Its  link, 
separately  multiplied  by  the  other  perpendicular  224  and  by  the  diagonal 
280,  and  divided  by  the  other  complement  I68,  gives  quotients  64  the  lower 
portion  of  the  perpendicular,  and  80  the  lower  portion  of  the  diagonal. 

So  for  the  second  perpendicular  224,  its  link  132,  severally  multiplied  by 
the  other  perpendicular  189  and  by  the  diagonal  315,  and  divided  by  the 
other  complement  252,  gives  99  for  the  lower  portion  of  the  perpendicular 
and  165  for  that  of  the  diagonal. 

197.  Rule  to  find  the  perpendicular  below  the  intersection  of  the  diago- 
nals :  The  perpendiculars,  multiplied  by  the  base  and  divided  by  the  re- 
spective complements,  are  the  erect  poles :  from  which  the  perpendicular 
let  fall  from  the  intersection  of  the  diagonals,  as  also  the  segments  of  the 
base,  are  to  be  found  as  before.* 

Statement :  Proceeding  as  directed,  the  erect  poles  are  found  225  and  400. 
Whence,  by  a  former  rule  (§  159),  the  perpendicular  below  the  intersection 

'  Sand'hi  union,  alliance  ;  intervention,  connecting  link. 
Pit'/ia  lit.  stool.     Here  the  complement  of  the  segment. 
»  By  the  rule  I  159. 


PLANE    FIGURE.  85 

of  die  diagonals  is  deduced,  144;  and  the  segments  of  the  base  108  and  192. 
See  figure 


2251^ 


400 


198 — 200.  Rule  to  find  the  perpendicular  of  the  needleS  its  legs  and  the 
segments  of  its  base  [three  stanzas]  :  The  proper  link,  multiplied  by  the 
other  perpendicular  and  divided  by  its  own,  is  termed  tiie  mean;^  and  the 
sum  of  this  and  the  opposite  link  is  called  the  divisor.  Those  two  quanti- 
ties, namely,  the  mean  and  the  opposite  link,  being  multiplied  by  the  base 
and  divided  by  that  divisor,  will  be  the  respective  segments  of  the  needle's 
base.  The  other  perpendicular,  multiplied  by  the  base  and  divided  by  the 
divisor,  will  be  the  perpendicular  of  the  needle.  The  flanks,  multiplied  by 
the  perpendicular  of  the  needle  and  divided  by  their  respective  perpendicu- 
lars,  will  be  the  legs  of  the  needle.'^     Thus  may  the   subdivision   of  a 

'  Such'i,  needle;  the  triangle  formed  by  the  flanks  of  the  trapezium  produced  until  they  meet. 

SantTAi.     See  preceding  note. 

Soma,  mean  ;  a  fourth  proportional  to  the  two  perpendiculars  and  the  link  or  segment. 

Jiara,  divisor ;  the  sum  of  such  fourth  proportional  and  the  other  link  or  segment. 

'  The  needle,  or  figure  resulting  from  the  prolongation  of  the  flanks  of  the  trapezium,  is  a  tri- 
angle, of  which  the  sides  are  those  prolonged  flanks;  and  the  base,  the  same  with  the  base  of  the 
trapezium  ;  and  the  perpendicular,  the  perpendicular  of  the  needle  :  to  find  which,  another  similar 
and  interior  triangle  is  formed,  in  which  the  flank  of  the  trapezium  is  one  side,  and  a  line  drawn 
from  its  extremity  parallel  to  the  other  leg  of  the  needle  is  the  second  side  :  the  perpendicular  [of 
the  trapezium]  is  peqiendicular  [of  this  interior  triangle]  ;  the  link  is  one  segment  of  the  base ;  and 
the  mean,  as  it  is  called,  is  the  other.     See 


260    or  this  195, 


260 


<o  it* 

Here  to  find  the  segment  denominated  the  mean.     In  proportion  as  the  opposite  perpendicular  is 
less  or  greater  than  the  proper  perpendicular,  so  is  the  segment  termed  the  mean  less  or  greater 


86  LI'LA'VATr.  Chapter  VI. 

plane  figure  be   conducted  by  the  intelligent,    by  means  of  the  rule  of 
three.' 

Here  the  perpendicular  being  224,  its  link  is  132.  This,  multiplied  by 
the  other  perpendicular,  viz.  189,  and  divided  by  its  own,  viz.  224,  gives 
the  mean  as  it  is  named ;  ^.  The  sum  of  this  and  the  other  link  48  is 
the  divisor,  as  it  is  called,  '-^.  The  mean  and  other  link  taken  into  the 
base,  being  divided  by  this  divisor,  give  the  segments  of  the  needle's  base 
^Y  and  '"Yp.  The  other  perpendicular  189,  multiplied  by  the  base  and 
divided  by  the  same  divisor,  yields  the  perpendicular  of  the  needle  ^y. 
The  sides  195  and  260,  multiplied  by  the  needle's  perpendicular  and  divided 
by  their  own  perpendiculars  respectively,  viz.  189  and  224,  give  the  legs 
of  the  needle,  which  are  the  sides  of  the  trapezium  produced :    *-^  and 


tff .     See 


Thus,  in  all  instances,  under  this  head,  taking  the  divisor  for  the  argu- 
ment, and  making  the  multiplicand  or  multiplicator,  as  the  case  may  be,  the 
fruit  or  requisition,  the  rule  of  three  is  to  be  inferred  by  the  intelligent  ma- 
thematician. 

than  that  called  link  :  for,  according  as  the  side  contiguous  to  the  perpendicular  is  greater  or  less, 
so  is  the  parallel  side  also  greater  or  less  ;  and  so  likewise  is  the  segment  contiguous  thereto.  Hence 
this  proportion  with  the  opposite  perpendicular :  '  If  the  proper  perpendicular  have  this  its  segment, 
what  has  the  opposite  perpendicular  ?'  The  proportional  resulting  is  the  other  segment  termed  the 
mean  in  the  constructed  triangle  :  and  the  sum  of  that  and  of  the  other  segment  called  the  opposite 
link  will  be  the  base  of  the  constituted  triangle.  It  is  denominated  the  divisor.  To  find  the  perpen- 
dicular of  the  needle  and  the  corresponding  segments  of  its  base  accordingly,  the  proportion  is  this  : 
'  If  for  this  base  these  be  the  segments,  what  are  they  for  the  needle's  base,  which  is  equal  to  the 
entire  base  ?'  And,  '  for  that  base,  if  this  be  the  perpendicular,  what  is  the  perpendicular  for  the 
needle's  base,  which  is  equal  to  the  whole  base?'  and  to  find  the  legs  of  the  needle,  '  if  the  hypote- 
nuse answering  to  an  upright  equal  to  the  perpendicular  be  the  side  contiguous  to  it,  what  is  the 
hypotenuse  answering  to  an  upright  equal  to  the  perpendicular  of  the  needle  f  In  like  manner, 
the  other  leg  is  deduced  from  the  other  perpendicular.  Gan. 

'  From  one  part  of  a  figure  given,  another  member  of  it  is  deduced  by  the  intelligent,  through 
the  rule  of  proportion.  Sua. 


PLANE    FIGURE.  tf 

201.  Rule:*  When  the  diameter  of  a  circle'  is  multiplied  by  three 
thousand  nine  hundred  and  twenty-seven  and  divided  by  twelve  hundred 
and  fifty,  the  quotient  is  the  near*  circumference  :  or  multiplied  by  twenty- 
two  and  divided  by  seven,  it  is  the  gross  circumference  adapted  to  prac- 
tice.* 

202.  Example.  Where  the  measure  of  the  diameter  is  seven,  friend,  tell 
the  measure  of  the  circumference  :  and  where  the  circumference  is  twenty- 
two,  find  the  diameter. 

'  To  deduce  the  circumference  of  a  circle  from  its  diameter,  and  the  diameter  from  the  circum- 
ference. Gan. 

*  Vriita,  vartula,  a  circle. 

Vyasa,  rishcambha,  visMti,  vistira,  the  breadth  or  diameter  of  a  circle. 

Parld'hi,  pariddka,  vrltti,  nemi  (and  other  synonyma  of  the  felloe  of  a  wheel),  the  circumference 
or  compass  of  a  circle. 

'  Sucshma,  delicate  or  fine;  nearly  precise;  contrasted  w'nh  st'hula,  gross,  or  somewhat  less 
exact,  but  sufficient  for  common  purposes. — Gang.  Su'r. 

Brahmegupta  puts  the  ratio  of  the  circumference  to  the  diameter  as  three  to  one  for  the  gross 
value,  and  takes  the  root  of  ten  times  the  square  of  the  diameter  for  the  neat  value  of  the  circum- 
ference.    See  Arithm.  of  Brahm.  §40.     Also  Srid'hara's  Ga«'.  «(Jr. 

♦  As  the  diameter  increases  or  diminishes,  so  does  the  circumference  increase  or  diminish : 
therefore  to  find  the  one  from  the  other,  make  proportion,  as  the  diameter  of  a  known  circle  to 
the  known  circumference,  so  is  the  given  diameter  to  the  circumference  sought :  and  conversely, 
as  the  circumference  to  the  diameter,  so  is  the  given  circumference  to  the  diameter  sought. 

Further:  the  semidiameter  is  equal  to  the  side  of  an  equilateral  hexagon  within  the  circle:  as 
will  be  shown.  From  this  the  side  of  an  equilateral  dodecagon  may  be  found  in  this  manner : 
the  semidiameter  being  hypotenuse,  and  half  the  side  of  the  hexagon,  the  side  ;  the  square-root 
of  the  difference  of  their  squares  is  the  upright :  subtracting  which  from  the  semidiameter  the  re- 
mainder is  the  arrow  [or  versed  sine].  Again,  this  arrow  being  the  upright,  and  the  half  side  of 
the  hexagon,  a  side ;  the  square-root  of  the  sum  of  their  squares  is  the  side  of  the  dodecagon.     See 


£^ 


From  which,  in  like  manner,  may  be  found  the  side  of  a  polygon  with  twenty-four  sides  :  and  so 
on,  doubling  the  number  of  sides  in  the  polygon,  until  the  side  be  near  to  the  arc.  The  sum  of 
such  sides  will  be  the  circumference  of  the  circle  nearly.  Thus,  the  diameter  being  a  hundred, 
the  side  of  the  dodecagon  is  the  surd  673  ;  and  that  of  a  polygon  of  three  hundred  and  eighty-four 
sides  is  nearly  equal  to  the  arc.  By  computation  it  comes  out  the  surd  98683.  Now  the  pro- 
portion, if  to  the  square  of  the  diameter  put  at  a  hundred,  viz.  10000,  this  be  the  circumference, 
viz,  the  surd,  98683,  then  to  the  square  of  the  assumed  diameter  twelve  hundred  and  fifty,  viz. 
1562500,  what  will  be  the  circumference?     Answer:  the  root  3927  without  remainder.     Gan. 


.• 


88 


LI'LAVATI'. 


Chapter  VI. 


Statement : 


Answer :    Circumference  2 1  \tH,  or  gross  cir- 
cumtcrcDce  22. 


Statement : 


Reversing  multiplier  and  divisor,  the  diameter 
comes  out  7  -ji^j  or  gross  diameter  7. 


203.  Rule :  In  a  circle,  a  quarter  of  the  diameter  multiplied  by  the 
circumference  is  the  area.  That  multiplied  by  four'  is  the  net  all  around 
the  ball."  This  content  of  the  surface  of  the  sphere,  multiplied  by  the 
diameter  and  divided  by  six  is  the  precise  solid,  termed  cubic,  content 
within  the  sphere.' 

204.  Example.  Intelligent  friend,  if  thou  know  well  the  spotless 
Lildvati,  say  what  is  the  area  of  a  circle,  the  diameter  of  which  is  measured 
by  seven  ?  and  the  surface  of  a  globe,  or  area  like  a  net  upon  a  ball,  the 
diameter  being  seven  ?  and  the  solid  content  within  the  same  sphere  ? 

'  Or  rejecting  equal  multiplier  and  divisor,  the  circumference  multiplied  by  the  diameter  is  the 
surface.  Gan. 

*  Prishia-phala,  superficial  content :  compared  to  the  net  formed  by  the  string,  with  which 
cloth  is  tied  to  make  a  playing  ball. 

G'hana-phala,  solid  content:  compared  to  a  cube,  and  denominated  from  it  cubic. 

'  Dividing  the  circle  into  two  equal  parts,  cut  the  content  of  each  into  any  number  of  equal  an- 
gular spaces,  and  expand  it  so  that  the  circumference  become  a  straight  line.     See 

S2  22 


Then  let  the  two  portions  approach  so  as  the  sharp  angular  spaces  of  the  one  may  enter  into 
the  similar  intermediate  vacant  spaces  of  the  other :  thus  constituting  an  oblong,  of  which 
the  semi-diameter  is  one  side  and   half  the  circumference  the  other.      See       y]\[\[y|\liKUM 


22  or  21  jfjl 

The  product  of  their  multiplication  is  the  area.  Half  by  half  is  a  quarter.  Therefore  a  quarter 
of  the  diameter  by  the  circumference  is  equal  to  the  area. 

.  See  in  the  GolM'hy&ya  (spherics)  of  the  Sidd'h/inta-siromani,  a  demonstration  of  the  rule,  that 
the  surface  of  the  sphere  is  four  times  the  area  of  the  great  circle,  or  equal  to  the  circumference 
multiplied  by  the  diameter. 


•• 


PLANE    FIGURE.  $^. 

Answer :   Area  of  the  circle  38  f^H-     Super- 
Statement:     [ — - — )     ficial  content  of  the  sphere  153  J-iJ-f.     Solid  con- 
tent of  the  sphere  179  ifH- 

205 — 206.  Rule :  a  stanza  and  a  half.  The  square  of  the  diameter  being 
multiplied  by  three  thousand  nine  hundred  and  twenty-seven,  and  divided 
by  five  thousand,  the  quotient  is  the  nearly  precise  area ;  or  multiplied  by 
eleven  and  divided  by  fourteen,'  it  is  the  gross  area  adapted  to  common 
practice.  Half  the  cube  of  the  diameter,  with  its  twenty-first  part  added  to 
it,*"  is  the  solid  content  of  the  sphere. 

The  area  of  the  circle,  nearly  precise,  comes  out  as  before  38  ^~,  or 
gross  area  38  ^.     Gross  solid  content  179  !• 

206 — 207-  Rule :'  a  stanza  and  a  half.  The  simi  and  difference  of  the 
chord  and  diameter  being  multiplied  together,  and  the  square-root  of  the 
product  being  subtracted  from  the  diameter,  half  the  remainder  is  the  arrow.* 

To  demonstrate  the  rule  for  the  solid  content  of  the  sphere :  suppose  the  sphere  divided  into 
as  many  little  pyramids,  or  long  needles  with  an  acute  tip  and  square  base,*  as  is  the  number  by 
which  the  surface  is  measured  ;  and  in  length  [height]  equal  to  half  the  diameter  of  the  sphere  : 
the  base  of  each  pyramid  is  an  unit  of  the  scale  by  which  the  dimensions  of  the  surface  are  reckon- 
ed :  and,  the  altitude  being  a  semidiameter.  one-third  of  the  product  of  their  multiplication  is 
the  content:  for  a  needle-shaped  excavation  is  one-third  of  a  regular  equilateral  excavation,  aa 
■will  be  shown  [§  221].  Therefore  [unit  taken  into]  a  sixth  part  of  the  diameter  is  the  content  of 
one  such  pyramidical  portion  :  and  that  multiplied  by  the  surface  gives  the  solid  content  of  tha 
sphere.  Gan. 

1  Multiplied  by  22,  and  divided  by  (7  X  4)  28 ;  or  abridged  by  reduction  to  least  terms,  \^. 
See  Gas.  &c. 

*  Multiplied  by  22,  and  divided  by  (7x6)  42 ;  or  multiplied  by  11  and  divided  by  21.  Then 
21:11  ::2:ff  or  1+-^.     See  Gak.  &c. 

'  In  a  circle  cut  by  a  right  line,  to  find  the  chord,  arrow,  &c.  That  is,  either  the  chord,  the 
arrow,  or  the  diameter,  being  unknown,  and  the  other  two  given,  to  find  the  one  from  the  others, 

Gan.  Su'r. 

*  A  portion  of  the  circumference  is  a  bow.  The  right  line  between  its  extremities,  like  tho 
string  of  a  bow,  is  its  chord.     The  line  between  them  is  the  arrow,  as  resembling  one  set  on  a  bow. 

Gai/.  Si/r. 
Dhanush,  chtipa  and  other  synonyma  of  bow  ;  an  arc  or  portion  of  the  circumference  of  a  circle. 
J'v^,  jy^,  jyacA,  guiia,  maurvi  and  other  synonyma  of  bow-string  ;  the  chord  of  an  are. 
Sara,  uhu  and  other  synonyma  of  arrow ;  the  versed  sine. 

*  M&rd'han,  base :  lit.  bead  or  sLull.    Apa,  tip  or  point :  sbarp  tumuut 

N 


90 


LI'LAVATl'. 


Chapter  VI. 


The  diameter,  less  the  arrow,  being  multiplied  by  the  arrow,  twice  the 
square-root  of  tlie  product  is  the  chord.  The  square  of  half  the  chord  being 
divided  by  the  arrow,  the  quotient  added  to  the  arrow  is  pronounced'  to  be 
the  diameter  of  the  circle." 

208.  Example.  In  a  circle,  of  which  the  diameter  is  ten,  the  chord 
being  measured  by  six,  say  friend  what  is  the  arrow  :  and  from  the  arrow 
tell  the  chord;  and  from  chord  and  arrow,  the  diameter. 


1  By  teachers  :  that  is,  it  has  been  so  declared  by  the  ancients.  Gav. 

Brahmegupta  divides  the  square  of  the  chord  by  four  times  the  versed  sine.  See  Arithm.  of 
Braiim.  §  41. 

-  On  plane  ground,  with  an  arbitrary  radius,»  describe  a  circle  ;  and  through  the  centre  draw 
a  vertical  diameter  :  then,  on  the  circumference,  at  an  arbitrary  distance,  make  two  marks;  and 
the  line  between  them,  within  the  circle,  across  the  diameter,  is  the  chord ;  the  portion  of  the 
circumference  below  the  chord  is  the  arc  :  and  the  portion  of  the  diameter  between  the  chord  and 
arc  is  the  arrow.     Statement  of  a  circle  to  e.\hibit  these  lines 


Thus,  if  the  arrow  be  unknown,  to  find  it,  a  triangle  is  constituted  within  the  circle ;  where  the 
chord  is  side,  a  thread  stretched  from  the  tip  of  the  chord  over  the  diameter  to  the  circumference 
is  [hypotenuse  ;  and  a  line  uniting  their  extremities  is]  the  upright.  That  is  to  be  first  found.  The 
square-root  of  the  difference  of  the  squares  of  the  diameter  and  chord,  which  are  hypotenuse  and 
side,  is  the  upright.  But  the  product  of  their  sum  and  difference  is  the  difference  of  their  squares  : 
the  root  of  which  is  the  upright,  and  is  measured  on  the  vertical  diameter.  Thus  the  sum  of  the 
two  portions  of  the  diameter  is  equal  to  the  diameter.  Now,  under  the  rule  of  concurrence  (|  55), 
the  less  portion  only  being  required,  the  difference  is  subtracted  from  the  diameter;  and  the  re- 
mainder being  halved  is  the  arrow. 

To  deduce  the  chord  from  the  arrow:  another  triangle  is  constituted  within  the  circle;  wherein 
the  semidiameter  less  the  arrow  is  the  upright,  the  semidiameter  is  hypotenuse  ;  and  the  square- 
root  of  the  differences  of  these  squares  will  be  the  half  of  the  chord  ;  and  this  doubled  is  the 
chord. 

Now  to  find  the  diameter.  The  root  of  the  difference  of  the  squares  of  hypotenuse  and  upright 
before  gave  half  the  chord  :  now  the  square  of  this  will  be  the  difference  of  the  squares  of.hy- 
potenuse  and  upright.  That  being  divided  by  the  arrow  and  added  to  it,  the  result  is  the 
diameter.  Sur. 

The  following  rule  for  finding  the  arc  is  cited  by  Gan'i^sa  from  Aryabiiatta  :  "  Si.\  times  the 
square  of  the  arrow  being  added  to  the  square  of  the  chord,  the  square-root  of  the  sum  is  the  arc." 

*  Carcata;  compass;  lit.  a  crab;  meaning  the  radiiu. 
Cindra ;   centre. 


PLANE  FIGURE. 


91 


Statement :     Diameter  10.     When  the  chord  is  6,  the  lengtli  of  the  arrow- 
comes  out  1.     See 


(D 


Or,  arrow  1.  The  chord  is  founds.  Or  from  the  chord  and  arrow  the 
diameter  is  deduced  10. 

209—211.  Rule:'  three  stanzas.  By  103923,  84853,  70534,  60000, 
52055,  45922,  or  41031,  multiply  the  diameter  of  the  circle,  and  divide  the 
respective  products  by  120000;  the  quotients  are  severally,  in  their  order, 
the  sides  of  polygons,  from  the  triangle  to  the  enneagon,  [inscribed]  within 
the  circle.* 


*  To  find  the  sides  of  regular  inscribed  polygons.  Sua.  Gan. 

*  Divide  the  circumference  by  the  number  of  sides  of  the  polygon,  and  find  the  chord  of  the 
arc  which  is  the  quotient.  For  this  purpose  one  commentator  (Su'r.)  refers  to  the  subsequent 
rule  (§  213)  in  this  treatise;  and  another  (Gan.)  to  the  rule,  in  the  author's  astronomical  work, 
(Sidd'hinta)  for  finding  chords. 

Or  the  demonstration,  says  Gan'e's'a,  may  be  otherwise  given.  Describe  a  circle  with  any 
radius*  at  pleasure,  divide  it  into  three  equal  parts  and  mark  the  points;  and  from  those  points, 
with  the  same  radius,  describe  three  circles,  which  will  be  equal  in  circumference  to  the  first 
circle ;  and  it  is  thus  manifest,  that  the  side  of  the  regular  hexagon  within  the  circle  is  half  a 
diameter.      See 


The  side  of  a  triangle  [inscribed]  within  a  circle  is  the  upright ;  the  diameter  is  hypotenuse  and 
the  side  of  the  hexagon  is  side  of  the  rectangular  triangle.  See  the  same  figure.  Therefore  the 
square-root  of  the  difference  of  the  squares  of  the  semidiameter  and  diameter  is  the  side  of  the  equi- 
lateral [inscribed]  triangle  :  viz.  for  the  proposed  diameter  (120000)  103923. 

The  side  of  a  regular  tetragon  is  hypotenuse,  the  semidiameter  is  upright,  and  side.  See 
Wherefore  the  square-root  of  twice  the  square  of  the  semidiameter  is  the  side  of  the 
[inscribed]  tetragon :  viz.  for  the  diameter  assumed,  84853. 

The  side  of  the  regular  octagon  is  hypotenuse,  half  the  side  of  the  tetragon  is  upright,  and  the 
difference  between  that  and  the  semidiameter  is  the  side.     See 


Wherefore  the  square-root  of  the  sum  of  the  squares  of  the  half  the  side  of  the  tetragon  and  the 
semidiameter  less  the  half  side  of  the  tetragon  is  the  side  of  the  regular  [inscribed]  octagon :  viz. 
for  the  diameter  as  put,  45922. 

*  Carcttta.     See  above, 
N  2 


9i 


LI'LAVATI'. 


Chapter  VI. 


212.  Example.  Within  a  circle,  of  which  the  diameter  is  two  thousand, 
tell  me  severally  the  sides  of  the  inscribed  equilateral  triangle  and  other 
polygons. 


The  proof  of  the  sides  of  the  regular  pentagon,  heptagon  and  euneagon  cannot  be  shown  in  a 
timilar  manner.  Gan. 

First  to  find  the  side  of  a  triangle  inscribed  within  the  circle,  describe  with  a  radius*  equal  to 
the  proposed  semidiameter,  a  circle;  and  draw  a  vertical  diameter  line  through  its  centre.  Then 
dividing  the  circumference  into  three  equal  parts,  draw  a  triangular  figure  and  another  opposite 
to  it;  let  two  other  diameters  join  the  summits  [angles]  of  those  triangles.  Thus  there  are  six 
angles  within  the  circle;  and  the  interval  between  each  pair  of  angles  is  equal  to  a  semidiameter: 
for  the  diameter,  which  is  in  contact  with  two  sides  of  a  quadrilateral  within  the  hexagon,  is,  from 
the  centre  of  the  circle  to  the  side,  a  quarter  of  a  diameter  above  the  centre  and  just  so  muck 
below  it;  and  the  sum  of  two  quarters  is  half  a  diameter. 


Now  the  length  of  a  chord  between  an  extremity  of  a  diameter  and  an  extremity  of  a  side  of  thff 
triangle,  is  equal  to  a  semidiameter.  It  is  a  side  of  a  rectangular  triangle,  of  which  the  diameter 
is  hypotenuse,  and  the  square-root  of  the  difference  of  their  squares  is  the  upright  and  is  the 
measure  of  the  side  of  the  inscribed  triangle.  Ex.  Diameter  120000.  Side  60OOO.  Difference  of 
their  squares  10800000000.     Its  square-root  103923. 

Or  a  hexagon  being  described  within  the  circle  as  before,  and  three  diameters  being  drawn 
through  the  centre  to  the  six  angles,  three  equilateral  quadrangular  figures  are  constituted,  where- 
in the  four  sides  are  equal  to  semidiameters  :  the  short  diagonal  too  is  equal  to  a  semidiameter  ; 
and  the  long  diagonal  is  equal  to  the  side  of  the  inscribed  triangle :  and  that  is  unknown.  To  find 
it,  put  the  less  diagonal  equal  to  the  semidiameter  and  proceeding  as  directed  by  the  rule  (§  IS  1-2), 
the  greater  diagonal  is  found,  and  is  the  side  of  the  inscribed  triangle.  Example :  assumed  dia- 
gonal 60000.  Its  square  36OOOOOOOO,  subtracted  from  four  times  the  square  of  the  side 
14400000000,  leaves  10800000000.  Its  square-root  is  the  greater  diagonal  103923;  and  is  the 
tide  of  the  inscribed  triangle. 

The  method  of  finding  the  side  of  the  triangle  and  of  the  hexagon  has  been  thus  shown.  That 
of  the  inscribed  tetragon  is  next  propounded.  Describing  a  circle  as  before,  draw  through  the 
centre  a  diameter  east  and  west  and  one  north  and  south  :  and  four  lines  are  to  be  then  drawn  in 
the  manner  of  chords,  uniting  their  extremities.  Thus  a  tetragon  is  inscribed  in 
the  circle.  In  each  quadrant,  another  rectangular  triangle  is  formed;  where- 
in a  semidiameter  is  side,  and  a  semidiameter  also  upright;  and  the  square-root 
of  ^he  sum  of  their  squares  will  be  the  side  of  the  tetragon.  For  example,  in 
the  proposed  instance,  side  6OOOO,  upright  6OOOO.  Sum  of  their  squares  7200000000.  Its  square- 
root  84853. 

The  side  of  the  pentagon  is  the  square-roof  of  five  limes  the  square  of  the  radius  less  the  radius.t 

•  Careata ;  opening  of  the  compasses.     See  above, 
t  Tryi/d;  sine  of  three  signs. 


I 


PLANE    FIGURE.  93 

Statement  : 


Answer:     Side  of  the  triangle  1732  ^VJ  of  the  tetragon  1414-^-;  of  the 

Or  describing  a  circle  as  before,  and  dividing  it  into  five  equal  parts,  construct  a  pentagon  within 
the  circle.  Draw  aline  between  the  extremities  of  two  sides  at  pleasure;  and  two  figures  are 
thus  formed;  one  of  which  is  a  trapezium,  and  the  other  a  triangle:  and  the  line  drawn  is  the 
common  base  of  both.  Assume  that  chord  arbitrarily  :  its  arrow,  found  as  directed, 
will  be  the  perpendicular.  Thus,  in  the  same  triangle,  two  rectangular  tri- 
angles are  constituted ;  in  which  half  the  base  is  the  side,  the  perpendicular  is  up- 
right, and  the  square-root  of  the  sum  of  their  squares  is  hypotenuse,  and  is  the 
side  of  the  pentagon.  Example  :  putting  the  length  of  the  arbitrary  chord  which  is 
the  base  of  the  two  figures,  at  a  value  near  to  the  diameter,  viz.  114140,  the  arrow  comes  out  by 
the  rule  (§  206)  41433  ;  and  the  side  of  the  pentagon  is  thence  deduced  70534. 

The  side  of  the  hexagon  is  half  the  diameter,  as  before  shown. 

For  the  heptagon,  describe  a  circle  as  before,  and  within  it  a  heptagon ;  draw  a  line  between 
the  extremities  of  two  sides  at  pleasure,  and  three  lines  through  the  centre  to  the  angles  indicated 
by  those  sides :  an  unequal  quadrilateral  is  thus  formed  :  of  which  the  two  greater  sides,  as  well 
as  the  least  diagonal,  are  equal  to  a  semidiameter.  Assume  the  value  of  the  greater  diagonal  ar- 
bitrarily :  it  is  the  chord  of  the  arc  encompassing  two  sides.  Hence  finding  the  arrow  in  the  man- 
ner directed,  it  is  the  side  of  a  small  rectangular  triangle,  in  which  half  the  base  or  chord  is  the 
upright;  whence  the  hypotenuse  or  side  of  the  heptagon  is  deducible. 
Ex.  Putting  93804  for  the  chord;  the  arrow  inferred  from  it  is  22579;  and  the 
tide  of  the  heptagon  52055. 

Or  by  a  preceding  rule  (§  181)  the  short  diagonal,  equal  to  a  semidiameter,  is  the  base  of  the 
two  triangles  on  either  side  of  it.  The  perpendicular  thence  deduced  (§  l63 — 164)  being  doubled 
is  the  greater  diagonal. 

To  demonstrate  the  side  of  the  octagon  :  describe  a  circle  as  before  and  two  diameter  lines,  di- 
viding the  circle  into  four  parts.  Then  draw  two  sides  in  each  of  those  parts;  and  eight  angles  are 
thus  delineated.  The  line  between  the  extremities  of  two  sides,  in  form  of  a  chord,  is  the  side  of 
an  inscribed  tetragon.  The  line  from  the  center  of  the  circle  to  the  corner  of  the  side  is  equal  to 
half  the  diameter.  Thus  an  unequal  quadrilateral  is  constituted ;  which  is  divided  by  the  line 
across  it,  forming  two  triangles,  in  which  one  side  is  a  semidiameter  and  the  base  also  is  equal  to 
a  semidiameter;  and  half  the  side  of  the  inscribed  tetragon  is  the  perpendicular  :  whence  the  other 
tide  is  to  be  inferred.        ,^^[^^        I'  comes  out  45922. 


Next  the  proof  of  the  side  of  the  nonagon  is  shown.    A  circle  being  described  as  before,  in- 


94  ll'LA'VATl'.  Chapter  VI. 

pentagon  1175-^^;  of  the  hexagon  1000;  of  the  heptagon  867 -^.j;  of  the 
octagon  765^;  of  the  nonagon  683-H^.     See 


From  variously  assumed  diameters,  other  chords  are  deducible;  as  will  be 
shown  by  us  under  the  head  of  construction  of  sines,  in  the  treatise  on 
spherics. 

The  following  rule  teaches  a  short  method  of  finding  the  gross  chords. 

213.  Rule :  The  circumference  less  the  arc  being  multiplied  by  the  arc, 
the  product  is  termed  first.'  From  the  quarter  of  the  square  of  the  circum- 
ference multiplied  by  five,  subtract  that  first  product :  by  the  remainder 
divide  the  first  product  taken  into  four  times  the  diameter :  the  quotient 
will  be  the  chord." 


scribe  a  triangle  in  it.  Thus  the  circle  is  divided  into  three  parts.  Three  equal  chords  being  drawn 
in  each  of  those  portions,  an  enneagon  is  thus  inscribed  in  the  circle :  and  three  oblongs  are  forraed 
within  the  same  ;  of  which  the  base  is  equal  to  the  side  of  the  inscribed  triangle.  Two  perpendi- 
culars being  drawn  in  the  oblong,  it  is  divided  into  three  portions,  the  first  and  last  of  which  are 
triangles ;  and  the  intermediate  one  is  a  tetragon.  The  base  in  each  of  them  is  a  third  part  of  the 
side  of  the  inscribed  triangle.  It  is  the  upright  of  a  reclangular  triangle;  the  perpendicular  is  its 
side ;  and  the  square-root  of  the  sum  of  their  squares  is  hypotenuse,  and  is  the  side  of  the  enneagon. 


To  find  the  perpendicular,  put  an  assumed  chord  equal  to  half  the  chord  of  the  [inscribed]  tetra- 
gon ;  find  its  arrow  in  the  manner  directed ;  and  subtract  that  from  the  arrow  of  the  chord  of  the 
[inscribed]  triangle  :  the  remainder  is  the  perpendicular.  Thus  the  perpendicular  comes  out 
21989  :  it  is  the  side  of  a  rectangular  triangle.  The  third  part  of  the  inscribed  triangle  is  34641  : 
it  is  the  upright.  The  square-root  of  the  sum  of  their  squares  is  41031  :  and  is  the  side  of  the 
inscribed  enneagon.     Thus  all  is  congruous.  Su'r. 

1  Frat'hama,  <jdt/a,  first  [product]. 

*  This,  according  to  the  remark  of  the  commentators,  is  merely  a  rough  mode  of  calculation, 
giving  the  gross,  not  the  near,  nor  precise,  chords.  The  rule  appears  from  their  explanations  of 
the  principle  of  it,  to  be  grounded  on  considering  the  circle  as  converted  into  a  rectangular 
triangle,  in  which  the  proposed  arc  is  a  side,  its  complement  to  the  semicircle  is  the  up- 
right, and  the  other  semicircle  is  hypotenuse.  The  difference  between  the  squares  of  such  up" 
right  and  hypotenuse  is  the  square  of  the  arc  and  is  the^rst  product  in  the  rule.     When  the  pro- 


PLANE   FIGURE.  95 

214.  Example.  Where  the  semidiameter  is  a  hundred  and  twenty,  and 
the  arc  of  the  circle  is  measured  by  an  eighteenth  multiplied  by  one  and  so 
forth  [up  to  nine/]  tell  quickly  the  chords  of  those  arcs. 

Statement :     Diameter  240.     Here  the  circumference  is  754  [nearly]. 

Arcs  being  taken,  multiples  of  an  eighteenth  thereof,  the  chords  are  to  be 
sought. 

Or  for  the  sake  of  facility,  abridging  both  circumference  and  arcs  by  the 
eighteenth  part  of  the  circumference,  the  same  chords  are  found.  Thus, 
circumference  18.  Arcs  ].  2.  3.  4.  5.  6.  7.  S.  9-  Proceeding  as  directed,  the 
chords  come  out  42.  82.  120.  154.  184.  208.  226.  236.  240.     See 


In  like  manner,  with  other  diameters  [chords  of  assigned  arcs  may  be 
found.]* 

215.  Rule  :'  The  square  of  the  circumference  is  multiplied  by  a  quarter 
of  the  chord  and  by  five,  and  divided  by  the  chord  added  to  four  times  the 
diameter;  the  quotient  being  subtracted  from  a  quarter  of  the  square  of  the 
circumference,  the  square-root  of  the  remainder,  taken  from  the  half  of  the 
circumference,  will  leave  the  arc* 

posed  arc  is  a  semicircle,  the  chord  is  a  niaxinium  :  and  so  is  the'first  product ;  and  this  is  equal  to 
the  square  of  the  semicircumference  or  quarter  of  the  square  of  the  circumference.  Then,  as  this 
maximum  is  to  the  greatest  chord,  or  four  times  the  one  to  four  times  the  other,  so  is  the  first 
product  for  the  proposed  arc  to  the  chord  of  that  arc.  This  proportion,  however,  is  modified,  by 
adding  to  the  first  term  of  it  the  square  of  the  complement  of  the  proposed  arc  to  the  semicircle. 

1  Up  to  nine,  or  half  the  number  of  arcs:  for  the  chords  of  the  eighth  and  tenth  will  be  the 
same ;  and  so  will  those  of  the  seventh  and  eleventh :  and  so  forth.  Gan. 

«  Gang.  &c. 

'  To  find  the  arc  from  the  chord  given. 

♦  This  is  analogous  to  the  preceding  rule.  The  complement  of  the  arc  is  found  by  a  rough  ap- 
proximation. 


96  LI'LA'VATI'.  Chapter  VI. 

216.  Example.  From  the  chords,  which  have  been  here  found,  now 
tell  the  length  of  the  arcs,  if,  mathematician,  thou  have  skill  in  computing 
the  relation  of  arc  and  chord.*  . 

Statement:     Chords  42.  82.  120.   154.   184.  208.  226.  236.  240. 
Circumference  abridged  18.     Arcs  thence  found  1.  2.  3.  4.  5.  6.  7-  8.  9- 
They  must  be  multiplied  by  the  eighteenth  part  of  the  circumference.* 

•  To  find  the  area  of  the  bow  or  segment  of  a  circle,  the  following  rule  is  given  in  Vishx'c* 
Ganila-sdra,  as  cited  by  Ganga'diiara;  and  the  like  rule  is  taught  by  Ce's'ava  quoted  by  his  son 
Gan'e's'a  :  '  The  arrow  being  multiplied  by  half  the  sum  of  the  chord  and  arrow,  and  a  twentieth 
part  of  the  product  being  added,  the  sum  is  the  area  of  the  segment.'  Sri'd'haua's  rule,  as  cited 
by  Gan'es'a,  is  '  the  square  of  the  arrow  multiplied  by  half  the  sum  of  the  chord  and  arrow,  being 
multiplied  by  ten  and  divided  by  nine,  the  square-ruot  of  the  product  is  the  area  of  the  bow. 
jGakes'a  adds :  '  the  chord  and  arrow  being  given,  find  the  diameter;  and  from  this  the  circum- 
ference; and  thence  tlie  arc.  Then  from  the  extremities  of  the  arc  draw  lines  to  the  centre  of 
the  circle.  Find  the  area  of  the  sector*  by  multiplying  half  the  arc  by  the  semidiameter;  and  the 
area  of  the  triangle  by  taking  half  the  chord  into  the  semidiameter  less  the  arrow.  Subtracting 
the  area  of  the  triangle  from  the  area  of  the  sector,  the  difference  is  the  area  of  the  segment.'  The 
Manoranjana  gives  a  similar  rule :  but  finds  the  area  of  the  sector  by  the  proportion  '  as  the  whole 
rircumference  is  to  the  whole  area,  so  is  the  proposed  arc  to  the  area  of  the  sector.' 

*  The  commentator  Su'ryada'sa  notices  other  figures  omitted,  as  he  thinks,  by  the  author; 
and  Ganga'dhara  quotes  from  the  Ganita-s6ra  of  Vishnu  an  enumeration  of  them ;  the  most 
material  of  which  are  specified  in  Srid'hara's  Ganita-s&ra.  They  are  reducible,  however,  ac- 
cording to  these  authors,  to  the  simple  figures  which  have  been  treated  of:  and  the  principal  ones 
are,  the  Gaja-danta  or  elephant's  tusk,  which  may  be  treated  as  a  triangle. — Sri.  Bdlendu,or  cres- 
cent, [a  lunule  or  meniscus,]  which  may  he  considered  as  composed  of  two  triangles. — Sei.  Yaca 
or  barley-corn,  [a  convex  lens,]  treated  as  consisting  either  of  two  triangles  or  two  bows, — Gang. 
Nemi  or  felloe,  considered  as  a  quadrilateral. — Sui.  and  Su'r.  ria/Va  or  thunderbolt,  treated  as 
comprising  two  triangles. — Su'r.  Or  a  quadrilateral  with  two  bows  or  two  trapezia. — Gang.  Or 
two  quadrilaterals. — Sri.  Panchacona  or  pentagon,  composed  of  a  triangle  and  a  trapezium. — 
Gang.  Shddbhvja  or  hexagon,  a  quadrilateral  and  two  triangles,  or  two  quadrilaterals. — Gang. 
5a/)/(Jira  or  heptagon,  five  triangles. — Gang.  Besides  Sanc'Aa  or  conch  ;  M/ifcian^aor  great  drum i 
^nd  several  others. 

•  Vrltta-e'hwda,  portion  of  a  circle, 


/ 


'^■^. 


CHAPTER  VII. 


EXCAVATIONS'  and  CONTENT  of  SOLIDS. 

217 — 218.  Rule  :*  a  couplet  and  a  half.  Taking  the  breadth  in  several 
places,'  let  the  sum  of  the  measures  be  divided  by  the  number  of  places : 
the  quotient  is  the  mean  measure.*  So  likewise  with  the  length  and  depth.* 
The  area  of  the  plane  figure,  multiplied  by  the  depth,  will  be  the  number 
of  soHd  cubits  contained  in  the  excavation. 

219 — 220.  Example:  two  stanzas.  Where  the  length  of  the  cavity, 
owing  to  the  slant  of  the  sides,  is  measured  by  ten,  eleven  and  twelve  cu- 
bits in  three  several  places,  its  breadth  by  six,  five  and  seven,  and  its  depth 

•  Ohdta-vyavahdra.  The  author  treats  first  of  excavations ;  secondly  of  stacks  of  bricks  and  the 
like;  thirdly  of  sawing  of  timber  and  cutting  of  stones;  and  fourthly  of  stores  of  grain;  in  as  many 
distinct  chapters. 

*  For  measuring  an  excavation,  the  sides  of  which  are  trapezia.  Gan. 
'  Vist6ra,  breadth. 

Dairghya,  length. 

Bed' ha,  bed'/iana,  depth. 

CMta,  an  excavation,  or  a  cavity  (garta),  as  a  pond,  well,  or  fountain,  &c. 

Sama-c'Adta,  a  cavity  having  the  figure  of  a  regular  solid  with  equal  sides  :  a  parallelipipedon, 
cylinder,  &c. 

Vishama-c'Mta,  one,  the  sides  of  which  are  unequal:  an  irregular  solid. 

SItchi-c'hdta,  an  acute  one  :  a  pyramid  or  cone. 

Sama-miti,  mean  measure. 

G'hana-phala,  g'hana-haita-sanc'ht/d,  c'Mta-sanc'hy&,  the  content  of  the  excavation  ;  or  of  a  solid 
alike  in  tigure. 

♦  The  greater  the  number  of  the  places,  the  nearer  will  the  mean  measure  be  to  to  the  truth, 
and  the  more  exact  will  be  the  consequent  computation.  Gan. 

'  The  irregular  solid  is  reduced  to  a  regular  one,  to  find  its  content.  ,■  ^i'  j,-jr       Si/r. 

O 


\ 


98  LI'LA'VATI'.  Chapter  VII. 

by  two,  four  and  three;  tell  me,  friend,  how  many  solid  cubits  are  contained 
in  that  excavation  ? 

Statement:  12  11  10  L.  Here  finding  the  mean  measure,  the 
7  5  6  B.  breadth  is  6  cubits,  the  length  1 1,  and 
3       4       2D.         the  depth  3.     See 


ndtt 


s» 


11 


Answer.    The  number  of  solid  cubits  is  found  198. 


221.  Rule:*  a  couplet  and  a  half  The  aggregate  of  the  areas  at 
the  top  and  at  the  bottom,  and  of  that  resulting  from  the  sum  [of  the  sides 
of  the  summit  and  base],  being  divided  by  six,  the  quotient  is  the  mean 
area:  that,  multiplied  by  the  depth,  is  the  neat-  content.^  A  third  part  of  the 
content  of  the  regular  equal  solid  is  the  content  of  the  acute  one.* 

222.  Example.  Tell  the  quantity  of  the  excavation  in  a  well,  of  which 
the  length  and  breadth  are  equal  to  twelve  and  ten  cubits  at  its  mouth,  and 
half  as  much  at  the  bottom,  and  of  which  the  depth,  friend,  is  seven  cubits. 

12 

Statement:  Length  12.     Breadth  10.     Depth  7.     |^^^  Sum  of 

the  sides  18  and  15. 

Area  at  the  mouth  120;  at  the  bottom  30;  reckoned  by  the  sum  of  the 
aides  270.     Total  420.     Mean  area  70.     Solid  content  490. 

'  To  find  the  content  of  a  prism,  pyramid,  cylinder  and  cone. 

*  Contrasted  with  the  result  of  the  preceding  rule,  which  gave  a  gross  or  approximated  measure. 
'  Half  the  sum  of  the  breadth  at  the  mouth  and  bottom  is  the  mean  breadth ;  and  half  the 

sum  of  the  length  at  the  mouth  and  bottom  is  the  mean  length  :  their  product  is  the  area  at  the 
middle  of  the  parallelipipedon.  [Four  times  that  is  the  product  of  the  sums  of  the  length  and 
breadth.]  This,  added  to  once  the  area  at  the  mouth  and  once  the  area  at  the  bottom,  is  six  times 
the  mean  area.  Gak. 

*  As  the  bottom  of  the  acute  excavation  is  deep,  by  finding  an  area  for  it  in  the  manner  before 
directed,  the  regular  equal  solid  is  produced:  wherefore  proportion  is  made  ;  if  such  be  the  con- 
tent, assuming  three  places,  what  is  the  content  taking  one?  Thus  the  content  of  the  regular  equal 
lolid,  divided  by  three,  is  that  of  the  acute  one.  Sv'r. 


EXCAVATIONS. 


99 


223.  Example.  In  a  quadrangular  excavation  equal  to  twelve  cubits, 
what  is  the  content,  if  the  depth  be  measured  by  nine  ?  and  in  a  round  one, 
of  which  the  diameter  is  ten  and  depth  five  ?  and  tell  me  separately,  friend, 
the  content  of  both  acute  solids. 


Statement : 


Product  of  the  side  and  upright  144 ;  mul- 
tiplied by  the  depth,  is  the  exact  content  1296. 
Content  of  the  acute  solid  432. 


Statement 


Content  nearly  exact 


of  the   acute  solid 


Or  gross  content  [of  the  cylinder] 
[of  the  cone]  ^f . 


1309 
10 


8750 
7 


\ 


mi  ajj  t. 


;  Hi  ,u: 


OS 


CHAPTER   VIII. 


la^-WK^ 


stacks: 


224 — 225.  Rule  :*  a  stanza  and  a  half.  The  area  of  the  plane  figure  [or 
base]  of  the  stack,  multiplied  by  the  height,'  will  be  the  solid  content. 
The  content  of  the  whole  pile,  being  divided  by  that  of  one  brick,  the  num- 
ber of  bricks  is  found.  The  height  of  the  stack,  divided  by  that  of  one  brick, 
gives  the  number  of  layers.     So  likewise  with  piles  of  stones.* 

226 — 227-  Example :  two  stanzas.  The  bricks  of  the  pile  being  eighteen 
fingers  long,  twelve  broad  and  three  high,  and  the  stack  being  five  cubits 
broad,  eight  long,  and  three  high,  say  what  is  the  solid  content  of  that  pile? 
and  what  the  number  of  bricks  ?  and  how  many  the  layers  ? 


Statement ; 


K 


Bricks  \,  \, 


Answer :     Solid  content  of  the  brick  -^ ; 
bricks  2560.     Number  of  layers  24. 

So  likewise  in  the  case  of  a  pile  of  stones. 


of  the  stack  120.     Number  of 


*  Chiti-w/axah&ra. 

*  To  find  the  solid  content  of  a  stack  or  pile  of  bricks,  or  of  stones  or  other  things  of  uniform 
dimensions:  also  the  number  of  bricks  and  of  strata  contained  in  the  stack. 

'  Chiti :  a  pile  or  stack  :  an  oblong  with  quadrangular  sides. 
Uchch'hraya,  Uchch'hriti,  Auchchya,  height. 
Stara,  layer  or  stratum. 

*  The  principle  of  the  rule  is  obvious  :  being  the  extension  of  the  preceding  rule  concerning  the 
content  of  excavations,  to  a  solid  pile;  and  the  application  of  the  rule  of  proportion.        Gai/. 


CHAPTER    IX. 


i  'i^^Hlr 


S  A  W.' 


228.  Rule:  two  half  stanzas.*  Half  the  sum  of  the  thickness  at  both 
extremities,  multipHed  by  the  length  in  fingers ;  and  the  product  again  mul- 
tiplied by  the  number  of  sections  of  the  timber,  and  divided  by  five  hun- 
dred and  seventy-six,'  will  be  the  measure  in  cubits. 

229.  Example.  Tell  me  quickly,  friend,  what  will  be  the  reckoning 
in  cubits,  for  a  timber  the  thickness  of  which  is  twenty  fingers  at  the  root ; 
and  sixteen  fingers  at  the  tip,  and  the  length  a  hundred  fingers,  and  which 
is  cut  by  four  sections. 

__^  Half  the  sum  of  the  thickness  at 

Statement:      (^~  j^ii^^^^ff     the   two    extremities   18,    multi- 


plied by  the  length,  makes  1 800 ; 
and  by  the  sections,  7200;  divided  by  576,  gives  the  quotient  in  cubits  y. 

230.  Rule :  half  a  stanza.  But  when  the  wood  is  cut  across,  the  super- 
ficial measure  is  found  by  the  multiplication  of  the  thickness  and  breadth, 
in  the  mode  above  mentioned.* 

'  CracachiKycmaMra :  determination  of  the  reckoning  concerning  the  saw  (cracacha)  or  iron 
instrument  with  a  jagged  edge  for  cutting  wood.  Sc'r. 

*  The  concluding  half  of  one  stanza  begun  in  the  preceding  rule  (225),  and  the  first  half  of 
another  stanza  of  like  metre  completed  in  the  following  rule  (230). 

'  To  reduce  superficial  fingers  to  superficial  cubits. 

♦  If  the  breadth  be  unequal,  the  mean  breadth  must  be  taken ;  and  so  must  the  mean  thickness, 
as  before  directed,  if  that  be  unequal.  Gan.  Su'r. 


102 


LI'LAVATI'. 


Chapter  IX. 


S31.  Maxim,  The  price  for  the  stack  of  bricks  or  the  pile  of  stones,  or 
for  excavation  and  sawing,  is  settled  by  the  agreement  of  the  workman,  ac- 
cording to  the  softness  or  hardness  of  the  materials.* 

232.  Example.  Tell  me  what  will  be  the  superficial  measure  in  cubits, 
for  nine  cross  sections  of  a  timber,  of  wliich  the  breadth  is  thirty-two  fingers, 
and  thickness  sixteen. 


32 


Statement : 


16 


Answer :     8  cubits. 


'  This  is  levelled  at  certain  preceding  writers,  who  have  given  rules  for  computing  specific  prices 
or  wages,  as  Arya-bhatta  quoted  by  Gan'e's'a,  and  as  Brahmegupta  (see  Arithm.  of  Brahm. 
§  49) ;  particularly  in  the  instance  of  sawyen'  work,  by  varying  the  divisors  according  to  the  dif- 
ference of  the  timber. 


CHAPTER  X. 


MOUND'  of  GRAIN, 

233.  Rule.  The  tenth  part  of  the  circumference  is  equal  to  the  depth 
[height']  in  the  case  of  coarse  grain ;  the  eleventh  part,  in  that  of  fine ;  and 
the  ninth,  in  the  instance  of  bearded  com.'  A  sixth  of  the  circumference 
being  squared  and  multiplied  by  the  depth  [height],  the  product  will  be  the 
solid  cubits  :*  and  they  are  c'hdris  of  MagadhaJ 

234.  Example.     Mathematician,  tell  me  quickly  how  many  charis  are 

*  RAii-vyavah&ra  determination  of  a  mound,  meaning  of  grain. 

»  Bed'ha  depth.  See  §  217.  Here  it  is  the  perpendicular  from  the  top  of  the  mound  of  corn  t» 
the  ground. — Gan.  It  is  the  height  in  the  middle  from  the  ground  to  the  summit  of  the  mound 
of  grain. — Su'r. 

'  Anu,  sucshma-d'h&nya,  fine  grain,  as  mustard  seed,  &c. — Gan.  As  Paspalum  Kora,  &c. — 
Manor,     As  wheat,  &c. — Su'r. 

Ananu,  st'h&la-d'hdnya,  coarse  grain,  as  chiches  (Cicer  arietinum). — Gan.  and  Sua.  As  wheat, 
&c. — Manoranjana.     Barley,  &c. — Ch.  onBRAiiM. 

S&cin,  auca-d'Mnya,  bearded  com,  as  rice,  &c. 

The  coarser  the  grain,  the  higher  the  mound.  The  rule  is  founded  on  trial  and  experience; 
and,  for  other  sorts  of  grain,  other  proportions  may  be  taken,  as  Pi  or  \.0\,  or  12  times  the 
height,  equal  to  the  circumference. — Gan.  and  Su'r.  The  rule,  as  it  is  given  in  the  text,  is 
taken  from  Brahuegupta. — Arithm.of  Brahm.  §  50. 

*  This  is  a  rough  calculation,  in  which  the  diameter  is  taken  at  one-third  of  the  circumference. 
The  content  may  be  found  with  greater  precision  by  taking  a  more  nearly  correct  proportion  be- 
tween the  circumference  and  diameter.  Gai/. 

'  See  I  7.  The  proportion  of  the  c'h&r't  or  other  dry  measure  of  any  province  to  the  solid  cubit 
being  determined,  a  rule  may  be  readily  formed  for  computing  the  number  of  such  measures  in  a 
conical  mound  of  grain.  Gane's'a  accordingly  delivers  rules  by  him  devised  for  the  c'h&ri  of  JVan- 
iigr&ma  and  for  that  ol  Dcvagiri:  '  the  circumference  measured  by  the  human  cubit,  squared  and 


102 


LI'LA'VATI'. 


Chapter  IX. 


231.  Maxim.  The  price  for  the  stack  of  bricks  or  the  pile  of  stones,  or 
for  excavation  and  sawing,  is  settled  by  the  agreement  of  the  workman,  ac- 
cording to  the  softness  or  hardness  of  the  materials.' 

232.  Example.  Tell  me  what  will  be  the  superficial  measure  in  cubits, 
for  nine  cross  sections  of  a  timber,  of  which  the  breadth  is  thirty -two  fingers, 
and  thickness  sixteen. 


32 


Statement : 


16 


Answer :     8  cubits. 


'  This  is  levelled  at  certain  preceding  writers,  who  have  given  rules  for  computing  specific  prices 
or  wages,  as  Arya-biiatta  quoted  by  Gane's'a,  and  as  BRAHMEOUPTA(see  Arithm.  of  Brahm. 
§  ^9)  t  particularly  in  the  instance  of  sawyers'  work,  by  varying  the  divisors  according  to  the  dif* 
ference  of  the  timber. 


CHAPTER  X. 


MOUND'  of  GRAIN, 

233.  Rule.  The  tenth  part  of  the  circumference  is  equal  to  the  depth 
[height^]  in  the  case  of  coarse  grain ;  the  eleventh  part,  in  that  of  fine ;  and 
the  ninth,  in  the  instance  of  bearded  corn.'  A  sixth  of  the  circumference 
being  squared  and  multiplied  by  the  depth  [height],  the  product  will  be  the 
solid  cubits:*  and  they  are  chdris  oi  MagadhaJ 

234.  Example.     Mathematician,  tell  me  quickly  how  many  c'hdris  are 

*  RAii-vyavah&ra  determination  of  a  mound,  meaning  of  grain. 

»  Bed'ha  depth.  See  §  217-  Here  it  is  the  perpendicular  from  the  top  of  the  mound  of  corn  t* 
the  ground. — Gai/.  It  is  the  height  in  the  middle  from  the  ground  to  the  summit  of  the  mound 
of  grain. — Su'r. 

'  Atiu,  sucshma-d'h&nya,  fine  grain,  as  mustard  seed,  &c. — Gan.  As  Paspalum  Kora,  &c. — 
Manor,    As  wheat,  &c. — Sue. 

Ananu,  st'h&lo'd'hdnya,  coarse  grain,  as  chiches  (Cicer  arietinum). — Gan.  and  Su'r.  As  wheat, 
&c. — Manoranjana.     Barley,  &c. — Ch.  on  Brabm. 

S&cin,  iuca-d'Mni/a,  bearded  com,  as  rice,  &c. 

The  coarser  the  grain,  the  higher  the  mound.  The  rule  is  founded  on  trial  and  experipnce ; 
and,  for  other  sorts  of  grain,  other  proportions  may  be  taken,  as  9i  or  10^,  or  12  times  the 
height,  equal  to  the  circumference. — Gan.  and  Su'r.  The  rule,  as  it  is  given  in  the  text,  is 
taken  from  Braiimegupta. — Arithm.of  Brahm.  §  50. 

*  This  is  a  rough  calculation,  in  which  the  diameter  is  taken  at  one-third  of  the  circumference. 
The  content  may  be  found  with  greater  precision  by  taking  a  more  nearly  correct  proportion  be- 
tween the  circumference  and  diameter.  Gan. 

'  See  §  7.  The  proportion  of  the  c'Mri  or  other  dry  measure  of  any  province  to  the  solid  cubit 
being  determined,  a  rule  may  be  readily  formed  for  computing  the  number  of  such  measures  in  a 
conical  mound  of  grain.  Gan'e'sa  accordingly  delivers  rules  by  him  devised  for  the  c'hdri  of  xVaa- 
digrdma  and  for  that  of  Dhagiri:  '  the  circumference  measured  by  the  human  cubit,  squared  and 


104  LI'LAVATI'.  Chapter  X. 

contained  in  a  mound  of  coarse  grain  standing  on  even  ground,  the  circum- 
ference of  which  (mound)  measures  sixty  cubits  ?  and  separately  say  how 
many  in  a  Hke  mound  of  fine  grain  and  in  one  of  bearded  corn  ? 

Statement :         (  \    Circumference  60.     Height  6. 


o 


Answer:  600  c'A^^rf^  of  coarse  grain.  But  of  fine  grain,  height  ^,  and 
quantity  thence  deduced  ^^.  So,  of  bearded  com,  height  y,  and  quan- 
tity ^  charis. 

235.  Rule :  In  the  case  of  a  mound  piled  against  the  side  of  a  wall,  or 
against  the  inside  or  outside  of  a  comer  of  it,  the  product  is  to  be  sought 
with  the  circumference  multiplied  by  two,  four,  and  one  and  a  third;  and  is 
to  be  divided  by  its  own  multiplier.' 

236 — 237.  Example :  two  stanzas.  Tell  me  promptly,  friend,  the  num- 
ber of  solid  cubits  contained  in  a  mound  of  grain,  which  rests  against  the 
side  of  a  wall,  and  the  circumference  of  which  measures  thirty  cubits  ;  and 
that  contained  in  one  piled  in  the  inner  corner  and  measuring  fifteen  cubits; 
as  also  in  one  raised  against  the  outer  corner  and  measuring  nine  times  five 
cubits. 


divided  by  sixteen,  gives  the  chdn  of  Nandigr&tna  ;  and  by  sixty,  that  of  Devagiri.'*  He  further 
observes,  that  a  vessel  measuring  a  span  every  way  contains  a  mana ;  that  one  measured  by  a 
cubit  every  way,  taking  the  natural  human  cubit,  contains  eight  matias ;  and  that  the  cubit,  in- 
tended by  the  text,  is  a  measure  in  use  with  artisans,  called  in  vulgar  speech  goj  [or  gaz\ ;  and  a 
c'Mr't,  equal  to  such  a  sulid  cubit,  will  contain  twenty-five  matias  and  three  quarters. 

*  Against  the  wall,  the  mound  is  half  a  cone ;  in  the  inner  corner,  a  quarter  of  one ;  and 
against  the  outer  corner,  three  quarters.  The  circumference  intended  is  a  like  portion  of  a  cir- 
cular base ;  and  the  rule  finds  the  content  of  a  complete  cone,  and  then  divides  it  in  the  propor- 
tion of  the  part.     See  Gan.  &c. 

*  In  tlie  vernacolar  dialect,  Nmdigaon  and  Dfigir :  the  latter  U  better  knovm  by  the  name  of  Datiletabady  which 
the  Emperor  Mviiammcd  conferred  on  it  in  the  14t)i  century.  The  Hindus,  however,  have  continued  to  it  Its  ancient 
name  of  Divogiri,  inonntuin  of  the  gods.  Nandigrdma,  the  town  or  village  of  Kandi  (Siva's  bull  and  vehicle),  retains 
the  aniit|uc  name  ;  and  is  situated  about  65  miles  west  of  Divagiri ;  and  is  accordingly  said  by  this  commeatBlor  in  th» 
colophon  of  bis  work  to  be  near  that  remarkable  place. 


MOUND   OF    GRAIN. 


105 


Twice  the  first-mentioned  circum- 
ference is  60.     Four  times  the  next 
Statement :     (  j^  g^      rpj^^  j^^^^  multiplied  by  one 

and  a  third  is  likewise  60.  With 
these  the  product  is  alike  600.  This,  being  divided  by  the  respective  mul- 
tipliers, gives  the  several  answers,  300,  150  and  450.\ 


'  For  coarse  grain:  but  the  product  is  looo  fQ^  fine;  and  £"""1  for  bearded  corn:  and  the 
answers  are  ?"»".  lAS-O,  iM";  and  ^2^",  J-^as,  lioo.  Can.  &c. 


CHAPTER   XL 


SHADOW  of  a  GNOMON. 

238.  Rule.^  The  number  five  hundred  and  seventy-six  being  divided 
by  the  difference  of  the  squares  of  the  differences  of  both  shadows  and  of 
the  two  hypotenuses/  and  the  quotient  being  added  to  one,  the  difference 
of  the  hypotenuses  is  multiplied  by  the  square-root  of  that  sum ;  and  the 
product  being  added  to,  and  subtracted  from,  the  difference  of  the  shadows, 
the  moieties  of  the  sum  and  difference  are  the  shadows.* 

'  Clihiyi-vyavaMra  :  determination  of  shadow ;  that  is,  measurement  by  means  of  a  gnomon. 

*  The  difference  of  the  shadows,  and  difference  of  the  hypotenuses  being  given,  to  find  the  length 
of  the  shadows  and  hypotenuses.  Sua. 

This  rule  is  the  first  in  the  chapter,  according  to  all  the  commentators  except  Su'ryadasa,  who 
begins  with  the  next,  §  240 ;  and  places  this  after  §  244. 

'  Ch'h&yi,  bh6,  prabMi,  and  other  synonyma  :  shadow. 

Sancu,  nara,  nrt;  a  gnomon.     It  is  usually  twelve  fingers  long. 

Cania,  hypotenuse  of  the  triangle,  of  which  the  gnomon  is  the  perpendicular,  and  the  shadow 
the  base. 

♦  The  rule,  as  the  author  hints  in  the  example,  which  follows,  is  founded  on  an  algebraic  so- 
lution. It  is  given  at  length  in  the  commentary  of  GAiiESA.  The  gnomon  and  shadow,  with  the 
line  which  joins  their  extremities,  constitute  a  rectangular  triangle,  in  which  the  gnomon  is  the 
upright,  the  shadow  is  the  side,  and  the  line  joining  their  extremities  the  hypotenuse.  In  like 
manner  another  such  is  constituted  ;  and  joining  their  flanks,  a  triangle  is  formed.     See 


Herein  the  gnomon  is  the  perpendicular;  the  two  hypotenuses  are  the  sides ;  the  two  shadows  are 
the  segments  ;  and  the  sum  of  these  is  the  base.  Put  this  equal  toyaX;  and  to  pursue  the  inves- 
tigation, let  the  diflference  of  the  shadows  be  given  11 ;  and  the  difference  of  the  hypotenuses  7- 


I 


SHADOW    OF    A    GNOMON.  107 

239-  Example.  The  iugeuious  man,  who  tells  the  shadows,  of  which 
the  difFerence  is  measured  by  nineteen,  and  the  difference  of  hypotenuses  by 
thirteen,  I  take  to  be  thoroughly  acquainted  with  the  whole  of  algebra  as 
well  as  arithmetic. 

Statement:  DifFerence  of  the  shadows  I9.  Difference  of  hypotenuses 
13.     [Gnomon  12.] 

Difference  of  their  squares  I92.  By  this  divide  576:  quotients.  Add 
one.  Sum  4.  Square-root  2.  By  which  multiply  the  difference  of  hyjx)- 
tenuses  13:  product  26.  Add  it  to,  and  subtract  it  from,  the  difference  of 
the  shadows  19 ;  and  halve  the  sum  and  difference  :  the  shadows  are  found 
V  and  i. 

Then,  by  the  rule  of  concurrence  (§  55),  the  segments  are  ya  ^  ru  y  and  ya-^  ru  y .  The  square 
of  the  greater  segment,  added  to  the  square  of  the  perpendicular  twelve,  is  the  square  of  the 
greater  side :  !/a  I' ^  3"*  T  't^^-  This  is  one  side  of  an  equation.  The  difterence  of  the  squares 
of  the  segments  is  equal  to  the  difference  of  the  squares  of  the  sides  ;  as  has  been  before  shown 
(§  164,  note).  But  the  difference  of  squares  is  equal  to  the  product  of  the  sum  and  difference. 
Sum  ya  1 ;  diff.  ru  11  ;  product  i/a  11.  It  is  the  difference  of  the  squares  of  the  sides.  Divided 
by  the  difference  of  the  simple  quantities,  the  quotient  is  the  sum  ya  y.  The  sum  and  difference 
added  together  and  halved  give  the  greater  side  ya  ^  ru  ff .  Its  square  is  ya  v  ^J  ya  1^/ 
ru  ^^^.  It  is  the  second  side  of  the  equation.  Reducing  both  to  the  same  denomination  and  drop- 
ping the  denominator,  the  equation  becomes  _y«  o    49    ^a  1078    r«  34153.   Now,  when  equal  sub- 

ya  V  121    ya  1078    ru    2401 

traction  is  made,  the  residue  [or  remaining  coefficient]  of  the  square  of  the  unknown  is  the  dif- 
ference of  the  squares  of  the  differences  of  the  shadows  and  hypotenuses.  The  residue  of  the 
simple  unknown  term  is  nought.  The  absolute  numbers  on  both  sides  being  abridged  by  the 
square  of  the  difference  of  hypotenuses  as  common  divisor,  there  remains  on  one  side  of  the  equation 
the  square  of  the  difference  of  the  hypotenuses,  and  on  the  other  side  the  square  of  the  difference 
of  the  shadows  added  to  five  hundred  and  seventy-six.  Subtraction  of  like  quantities  being  made, 
the  residue  of  the  absolute  number  is  the  difference  of  the  squares  of  the  differences  of  the  hypote- 
nuses and  shadows  added  to  five  hundred  and  seventy-si.x.  The  remaining  term  involving  the 
square  of  the  unknown,  being  divided  by  the  coefficient  of  the  same,  gives  unity.  The  remainder 
of  the  absolute  number  being  abridged  by  the  common  divisor,  there  results  the  number  five  hun- 
dred and  seventy-six  divided  by  the  difference  of  the  squares  of  the  differences  of  the  shadows  and 
hypotenuses  together  with  one.  Its  square-root  is  the  root  of  the  absolute  number.  But  the  abso- 
lute number  was  previously  abridged  by  the  square  of  the  difference  of  the  hypotenuses :  where- 
fore the  root  must  be  multiplied  by  the  difference  of  the  hypotenuses.  Hence  the  rule  §  238.  It 
is  the  value  oi  yaxat-t&vat  as  found  by  the  equation  :  and  is  the  base.  It  is  the  sum  of  the  shadows. 
The  difference  of  the  shadows  being  added  and  subtracted,  the  moieties  will  be  the  shadows,  by 
the  rule  of  concurrence  (§  55).  Gan. 

P  2 


108 


LI'LAVATI. 


Chapter  XL 


Under  the  rule  §  1 34,  the  gnomon  being  the  upright,  and  the  shadow  the 
side,  the  square-root  of  the  sum  of  their  squares  is  the  hypotenuse ;  viz.  Y 
and  V' 

240.  Rule :'  half  a  stanza.  The  gnomon,  multiplied  by  the  distance 
of  its  foot  from  the  foot  of  the  light,  and  divided  by  the  height  of  the  torch's 
flame  less  the  gnomon,  will  be  the  shadow.* 

241.  Example.  If  the  base  between  the  gnomon  and  torch  be  three 
cubits,  and  the  elevation  of  the  light,  three  cubits  and  a  half,  say  quickly, 
friend,  how  much  will  be  the  shadow  of  a  gnomon,  which  measures  twelve 
fingers  ? 


Statement ; 


Answer  :     Shadow  12  fingers. 


242.  Rule :'  half  a  stanza.  The  gnomon  being  multiplied  by  the 
distance  between  the  light  and  it,  and  divided  by  the  shadow ;  and  the 
quotient  being  added  to  the  gnomon ;  the  sum  is  the  elevation  of  the  torch.* 


'  The  elevation  of  the  light  and  [horizontal]  distance  of  its  foot  from  the  foot  of  the  gnomon 
being  given,  to  find  the  shadow.  Gan. 

^  As  the  height  of  the  light  increases,  the  shadow  of  the  gnomon  decreases ;  and  as  the  light  is 
lowered,  the  length  of  the  shadow  augments.  Now  a  line  drawn  strait,  in  the  direction 
of  the  diagonal,  from  the  light,  meets  the  extremity  of  the  gnomon's  shadow.  In  like 
manner,  tailing  off  from  the  tip  of  the  torch's  flame  a  height  equal  to  the  gnomon's,  and  placing 
the  light  there,  a  diagonal  line  drawn  as  before  meets  the  base  of  the  gnomon. 
Thus  the  base  between  the  foot  of  the  gnomon  and  that  of  the  light  is  the  side  of 
the  triangle,  and  the  height  of  the  light  less  the  gnomon  is  the  upright.  Hence 
the  proportion :  '  as  the  height  of  the  torch  less  the  gnomon,  is  to  the  distance  of 
its  foot  from  that  of  the  gnomon,  so  is  the  gnomon  to  the  shadow.'  Whence  the 
rule. 

'  To  find  the  elevation  of  the  torch ;  the  length  of  the  shadow  being  given,  and  the  [horizontal] 
distance.  Su'r. 

♦  The  demonstration  proceeds  on  the  proportion  '  as  the  side  measured  by  the  shadow  of  the 
gnomon  is  to  an  upright  e(]ual  to  the  gnomon,  so  is  a  base  equal  to  tlie  distance  of  the  gnomon 
from  the  light,  to  a  proportional,'  which  is  the  elevation  of  the  torch  less  the  height  of  the  gnomon. 

Sua. 


Su'r. 


SHADOW   OF   A    GNOMON. 


109 


243.  Example.  If  the  base  between  the  torch  and  gnomon  be  three 
cubits,  and  the  shadow  be  equal  to  sixteen  fingers,  how  much  will  be  the 
elevation  of  the  torch  ?  And  tell  me  what  is  the  distance  between  the  torch 
and  gnomon  [if  the  elevation  be  given]  ? 


Statement : 


Answer :     Height  of  the  torch  V  • 


244.  Rule  :•  half  a  stanza.  The  shadow,  multiplied  by  the  elevation 
of  the  light  less  the  gnomon  and  divided  by  the  gnomon,  will  be  the  interval 
between  the  gnomon  and  light. 


Example,  as  before  proposed  (§  243). 


Answer:     Distance  3  cubits. 

245.  Rule  -.^  a  stanza  and  a  half.  The  length  of  a  shadow  multiplied 
by  the  distance  between  the  terminations  of  the  shadows  and  divided  by  the 
difference  of  the  length  of  the  shadows,  will  be  the  base.  The  product  of 
the  base  and  the  gnomon,  divided  by  the  length  of  the  shadow,  gives  the 
elevation  of  the  torch's  flame.' 

In  like  manner  is  all  this,  which  has  been  before  declared,  pervaded  by 
the  rule  of  three  with  its  variations,*  as  the  universe  is  by  the  Deity. 


'  To  find  the  [horizontal]  distance ;  the  elevation  of  the  torch  and  length  of  the  shadow  being 
given.  SuR.  and  Gan. 

The  gnomon  being  set  up  successively  in  two  places,   the  distance  between  which  is  known, 
and  the  length  of  the  two  shadows  being  given,  to  find  the  elevation  of  the  light,  and  the  base. 

SuR.  and  Gan. 
^  The  rule  is  borrowed  from  Brahmegupta.     See  Arithm.  of  Brahm.  §  54. 
♦  The  double  rule  of  proportion,  or  rule  of  five  or  more  quantities,  &c. — Gan.     The  author 
intimates,  that  the  whole  preceding  system  of  computation,  as  well  the  rules  contained  under  the 
present  head,  as  those  before  delivered,  is  founded  on  the  rule  of  proportion.  Gan. 


flOO  L  FLAT  ATI'.  Chapter  XI. 

246.  Example.  The  shadow  of  a  gnomon  measuring  twelve  fingers 
being  found  to  be  eight,  and  that  of  the  same  placed  on  a  spot  two  cubits 
further  in  the  same  direction  being  measured  twelve  fingers,  say,  intelligent 
mathematician,  how  much  is  the  distance  of  the  shadow^  from  the  torch,  and 
the  height  of  the  light,  if  thou  be  conversant  with  computation,  as  it  is 
termed,  of  shadow? 


Here  the  interval  between  the  termination 
Statement :  \\^  of  the  shadows  is  in  fingers  52 ;    and  the 

shadows  are  8  and  12.  The  first  of  these, 
viz.  8,  multiplied  by  the  interval  52,  and  di- 
vided by  the  difference  of  the  length  of  the  shadows  4,  gives  the  length  of 
the  base  104.  It  is  the  distance  between  the  foot  of  the  torch  and  the  tip 
of  the  first  shadow.  So  the  length  of  the  base  to  the  tip  of  the  second 
shadow  is  156. 

The  product  of  the  base  and  gnomon,  divided  by  the  shadow,  gives  both 
ways  the  same  elevation  of  the  light :  viz.  6-^  cubits. 

In  like  manner.]-  As  under  the  present  head  of  measurement  of  shadow, 
the  solution  is  obtained  by  putting  a  proportion :  viz.  '  if  so  much  of  the 
shadow,  as  is  the  excess  of  the  secoiid  above  the  first,  give  the  base  inter- 
cepted between  the  tips  of  the  shadows,  -what  will  the  first  give  ?'  Tlie 
distances  of  the  terminations  of  the  shadows  from  the  foot  of  the  torch  are 
in  this  manner  severally  found.  Then  a  second  proportion  is  put :  '  if,  the 
shadow  being  the  side,  the  gnomon  be  the  upright ;  then,  the  base  being  the 
side,  what  will  be  the  upright  ?'  The  elevation  of  the  torch  is  thus  found : 
and  is  both  ways  [that  is,  computed  with  either  shadow,]  alike. 

So  the  whole  sets  of  five  or  more  terms  are  explained  by  twice  putting 
three  terms  and  so  forth. 

As  the  being,  who  relieves  the  minds  of  his  worshippers  from  suffering, 
and  who  is  the  sole  cause  of  the  production  of  this  universe,  pervades  the 

'  All  the  commentators  appear  to  have  read  gnomon  in  thisplace;  but  one  copy  of  the  text 
exhibits  shadow  as  the  reading:  andtbis  seems.to  be  coricct. 
*  Reference  to  the  text:  §  245. 


SHADOW    OF   A    GNOMON.  ill 

whole,  and  does  so  with  his  various  manifestations,  as  worlds,  paradises,* 
mountains,  rivers,  gods,  demons,  men,  trees,"  and  cities ;  so  is  all  this  collec- 
tion of  instructions  for  computations  pervaded  by  the  rule  of  three  terms. 

Then  why  has  it  been  set  forth  by  so  many  different  [writers,^  with  much 
labour,  and  at  great  length]  ?     The  answer  is 

247.  Whatever  is  computed  either  in  algebra  or  in  this  [arithmetic]  by 
means  of  a  multiplier  and  a  divisor,  may  be  comprehended  by  the  sagacious 
learned  as  the  rule  of  three  terms.  Yet  has  it  been  composed  by  wise  in- 
structors in  miscellaneous  and  other  manifold  rules,  teaching  its  easy  varia- 
tions, thinking  thereby  to  increase  the  intelligence  of  such  dull  comprehen- 
sions as  ours. 

'  Bhuvana,  vioMs ;  heaven,  earth,  and  the  intermediate  region.  B/zarana,  paradises,  the  several 
abodes  of  Brahma'  and  the  rc«t  of  the  gods. 

*  Naga,  either  tree  or  mountain.  The  terra,  however,  is  read  in  the  text  by  none  of  the  com- 
mentators besides  Gan'es'a. 

3  As  SriVhaea  and  the  rest. — Mono.    As  Brahmegupta  and  others. — Gakg. 


CHAPTER     XII. 


PULVERIZER} 

248 — 252.     Rule.     In  the  first  place,  as  preparatory  to  the  investigation 

'  Cutlaca-vyavah&ra  or  cuttac&d'hy&ya  determination  of  a  grinding  or  pulverizing  multiplier,  or 
quantity  such,  that  a  given  number  being  multiplied  by  it,  and  the  product  added  to  a  given 
quantity,  the  sum  (or,  if  the  additive  be  negative,  the  difference)  may  be  divisible  by  a  given  di- 
visor without  remainder. 

See  Vija-Ganita,  chapter  2,  from  which  this  is  borrowed,  the  contents  being  copied,  (with  some 
variation  of  the  order,)  nearly  word  for  word.  For  this,  as  well  as  the*  following  chapter  13,  on 
Combination,  belongs  to  algebra  rather  than  arithmetic  ;  according  to  the  remark  of  the  commen- 
tator Gan'e's'a  bhat'ta  :  and  they  are  here  introduced,  as  he  observes,  and  treated  without  em- 
ploying algebraic  forms,  to  gratify  such  as  are  unacquainted  with  analysis. 

The  commentator  begins  by  asking  'why  this  subject  has  been  admitted  into  a  treatise  of  arith- 
metic, while  a  passage  of  Arya-bhat't'a  expressly  distinguishes  it  from  both  arithmetic  and  alge- 
bra: "  the  multifarious  doctrine  of  the  planets,  arithmetic,  the  pulverizer,  (cuitaca)  and  analysis 
(vija),  and  the  rest  of  the  science  treating  of  seen*  objects;"  and  Brahmegupta,  at  the  begin- 
ning of  his  chapter  on  Arithmetic,  excludes  it  from  this  head;  when  describing  the  complete  ma- 
thematician (see  Arithm.  of  Brahm.  §1)?  The  commentator  proceeds  to  answer, — 'Mathe- 
matics consist  of  two  branches  treating  of  known  and  of  unknown  quantity;  as  expressly  declared  : 
"  The  science  of  computation  (ganila)  is  pronounced  two-fold,  denominated  vi/acta  and  aiyacta 
(distinct  and  indistinct)."  The  investigation  of  the  pulverizer,  like  the  problem  of  the  affected 
square,  Cvarga-pracriti.  See  Vya-ganita,  ch.  3),  is  comprehended  in  algebra,  being  subservient 
to  its  solutions;  as  hinted  by  the  author.  (See  Vija.  §  99)-  The  separate  mention  of  the  head  of 
investigation  of  the  pulverizer,  in  passages  of  AavA-BHATTA  and  other  ancient  authors,  as  well  as 
in  those  of  Bha'scara  and  the  rest  ("  By  arithmetic,  by  algebra,  by  investigation  of  the  pulverizer, 
and  by  resolution  of  the  affected  square,  answers  are  found")  is  designed  as  an  intimation  of  the 
difficulty  and  importance  of  the  matter;  not  to  indicate  it  as  the  subject  of  a  separate  treatise:  and 
this,  no  less  than  the  head  of  combination   treated  in  the  next  chapter  (chapter  13),  with  other 

*  Seen,  or  physical;  as  opposed  (o  astrology,  which  is  considered  to  be  couvetgant  with  matters  of  an  unseen  and  spi- 
ritual nature,  the  invisible  influence  which  connects  effects  with  causes. 


PULVERIZER.  lis 

of  a  pulverizer,'  the  dividend,  divisor  and  additive  quantity*  are,  if  practi- 
cable, to  be  reduced  by  some  number.'  If  the  number,  by  which  the  divi- 
dend and  divisor  are  both  measured,  do  not  also  measure  the  additive  quan- 
tity, the  question  is  an  ill  put  [or  impossible]  one. 

249 — 251.  The  last  remainder,  when  the  dividend  and  divisor  are 
mutually  divided,  is  their  common  measure.'  Being  divided  by  that  com- 
mon measure,  they  are  termed  reduced  quantities.*     Divide  mutually  the 

topics  (all  exclusive  of  arithmetic,  whicli  comprises  logistics  and  the  rest  of  the  enumerated  heads 
terminating  with  measurement  by  shadow,)  falls  within  algebra,  as  the  precepts  of  the  rules  concur 
with  exercise  of  sagacity  to  etfect  the  solution.  (See  Fyo,  §224).  It  is  then  true,  concludes  this 
commentator,  that  mathematics  consist  but  of  two  branches.  Nevertheless  the  subjects  of  this 
and  of  the  following  chapter  are  here  introduced,  to  be  treated  without  reference  to  algebraic  so- 
lutions, as  the  Bhadra-gaiiita  and  other  problems*  have  found  place  in  the  arithmetical  treatises  of 
Naba'yan'a  and  other  writers,  to  be  there  wrought  without  algebra;  and  for  the  same  purpose  of 
gratifying  such  as  are  not  conversant  with  this  branch.  Gan. 

In  Biiahmegupta's  work  the  whole  of  algebra  is  comprised  under  this  title  of  Cullacdd'hyiya, 
chapter  on  the  pulverizer.  See  Brahh.  ch.  18,  and  Chaturvbda  on  Brahmegupta,  ch.  12, 
S66. 

'  Cuitaca  or  Cuiia,  from  cuti,  to  grind  or  pulverize;  (to  multiply  :  all  verbs  importing  tendency 
to  destruction  also  signifying  multiplication. — Gan.) 

The  term  is  here  employed  in  a  sense  independent  of  its  etymology  to  signify  a  multiplier  such, 
that  a  given  dividend  being  multiplied  by  it,  and  a  given  quantity  added  to  (or  subtracted  from) 
the  product,  the  sum  (or  difference)  may  be  measured  by  a  given  divisor.  Sub.  on  Vij.-gan.  and 
Lil.  Rang,  on  Fif*.  Gan,  on  Lil. 

The  derivative  import  is,  however,  retained  in  the  present  version  to  distinguish  this  from  mul- 
tiplier in  general ;  cuitaca  being  restricted  to  the  particular  multiplier  of  the  problem  in  question. 

*  Csfiepa,  or  cs/iepaca,  nryuti,  additive.  From  cship  to  cast  or  throw  in,  and  from  yu  to  mix.  A 
quantity  superinduced,  being  either  affirmative  or  negative,  and  consequently  in  some  examples 
an  additive,  in  others  a  subtractive,  term. 

VUuddHii,  subtractive  quantity,  contradistinguished  from  cshepa  additive,  when  this  is  restricted  to 
an  affirmative  one.     See  %  263. 

'  Apaxiartana,  abridgment;  abbreviation. — Gas.  Depression  or  reduction  to  least  terms  ;  di- 
vision without  remainder  :  also  the  number  which  serves  to  divide  without  residue;  the  common 
measure,  or  common  divisor  of  equal  division.  Su'r. 

*  DrtdCha,  firm :  reduced  by  the  common  divisor  to  the  least  term.  The  word  is  applicable  to 
the  reduced  additive,  as  well  as  to  the  dividend  and  divisor.  Brahmegupta  uses  nick'Mda  and 
nirapavarta  in  this  sense. — Brahm.  18,  §  9. 

*  Bhttdra-ganita,  on  the  construction  of  magical  squares,  &c  is  the  13th  head  termed  vyttvahira,  ai  Ancapita 
oo  combination  of  numerals,  is  the  14th,  in  NVbXyam'a's  treatise  of  arithmetic  entitled  CauTnudi. 


lie  LI'LAVATI'.  Chapter  XII. 

Or,  the  divisor  and  additive  quantity  are  reduced  by  the  common  measure 

nine.     Dividend  100     Additive  10. 
Divisor  7 

Here  the  quotients,  the  additive  and  cipher  make  the  series  14     Tl>e  miil- 

3 

10 

0 

tiplier  is  found  2,  which,  multiplied  by  the  common  measure  9.  gives  the 
true  multiplier  18. 

Or,  the  dividend  and  additive  are  reduced,  and  further  the  divisor  and  ad- 
ditive, by  common  measures.     Dividend  10      a  1 1  v       i 
'     •'  T\-  ■  r,     Additive   1. 

Divisor       7  . 

Proceeding  as  before,  the  series  is  1     The  multiplier  hence  deduced  is  2  ; 

2 
1 
0 

which,  taken  into  the  common  measure  9,  gives  18:  and  hence,  by  mul- 
tiplication and  division,  the  quotient  comes  out  30. 

Or,  adding  the  quotient  and  multiplier  as  found,  to  [multiples  of]  their  divi- 
sors, the  quotient  and  multiplier  are  1 30  and  81;  or  230  and  144;  and  so  forth.' 

256.  Rule:  half  a  stanza.  The  multiplier  and  quotient,  as  found  for  an 
additive  quantity,  being  subtracted  from  their  respective  abraders,  answer 
for  the  same  as  a  subtractive  quantity.'' 

Here  the  quotient  and  multiplier,  as  found  for  the  additive  quantity  ninety 
in  the  preceding  example,  namely  30  and  18,  being  subtracted  from  their 
respective  abraders,  namely  100  and  63;  the  remainders  are  the  quotient 
and  multiplier,  which  answer  when  ninety  is  subtractive  :  viz.  70  and  45. 

Or,  these  being  added  to  arbitrary  multiples  of  their  respective  abraders, 
the  quotient  and  multiplier  are  170  and  108;  or  270  and  131;  &c. 

257.  Example.'    Tell  mc,  mathematician,  the  multipliers  severally,  by 

■  As  330  and  201 ;  &c.  Gang. 

*  The  rule  serves  when  the  additive  quantity  is  negative. — Gaji'.  Su'r.  It  is  followed  in  the 
Vya-gariita  by  half  a  stanza  relating  to  the  change  induced  by  reversing  the  sign,  affirmative  or 
negative,  of  the  dividend.     See  V'lj.-gan.  §59. 

*  This  additional  example  is  unnoticed  by  Gan'es'a  ;  but  expounded  by  the  rest  of  the  com- 
mentators, and  found  in  all  copies  of  the  text  that  have  been  collated.  See  a  corresponding  one 
with  an  essential  variation  however  in  the  reading;  Vij.-gan.  §  67. 


PULVERIZER.  117 

which  sixty  being  multipHcd,  and  sixteen  being  added  to  the  product,  or 
subtracted  from  it,  the  sum  or  difference  may  be  divisible  by  thirteen  with- 
out a  remainder. 

Statement:     Dividend  60      a  i  r4.-       ,/? 
T->-  ■  ,0     Additive  16. 

Divisor      13 

The  series  of  quotients,  found  as  before,  is     4 

1 
1 
1 
1 
16 
0 

Hence  the  multipher  and  quotient  are  deduced  2  and  8.     But  the  quotients 

[of  the  series]  are  here  uneven :  wherefore  the  multiplier  and  quotient  must  be 

subtracted  from  their  abraders  13  and  6O:  and  the  multiplier  and  quotient, 

answering  to  the  additive  quantity  sixteen,  are  1 1   and  52.     These  being 

subtracted  from  the  abraders,  the  multiplier  and  quotient,  corresponding  to 

the  subtractive  quantity  sixteen,  are  2  and  8. 

258.  Rule  :'  a  stanza  and  a  half.  The  intelligent  calculator  should  take 
a  like  quotient  [of  both  divisions]  in  the  abrading  of  the  numbers  for  the 
multiplier  and  quotient  [sought].  But  the  multiplier  and  quotient  may  be 
found  as  before,  the  additive  quantity  being  [first]  abraded  by  the  divisor ; 
the  quotient,  however,  must  have  added  to  it  the  quotient  obtained  in  the 
abrading  of  the  additive.  But,  in  the  case  of  a  subtractive  quantity,  it  is 
subtracted. 

259.  Example.  What  is  the  multiplier,  by  which  five  being  multiplied 
and  twenty-three  added  to  the  product,  or  subtracted  from  it,  the  sum  or 
difference  may  be  divided  by  three  without  remainder. 

Statement:     Dividend  5      .  u-^. 

n-  •  c     Additive  23. 

Divisor       3 

Here  the  series  is     1     and  the  pair  of  numbers  found  as  before  46      They 
1  23 

S3 
0 

'  Applicable  when  the  additive  quantity  exceeds  the  dividend  and  divisor.  Ga>.     . 


118  LI'LAVATl'.  Chapter  XII. 

are  abraded  by  the  dividend  and  divisor  5     The  lower  number  being  abraded 

3 
by  3,  the  quotient  is  7  [and  residue  2].     The  upper  number  being  abraded 

by  5,  the  quotient  would  be  9  [and  residue  1]  :  nine,  however,  is  not  taken; 
but,  under  the  rule  for  taking  like  quotients,  seven  only,  [and  the  residue 
consequently  is  eleven].  Thus  the  multiplier  and  (juotient  come  out  2  and  1 1 . 
And  by  the  former  rule  (^  256)  the  multiplier  and  quotient  answering  to 
the  same  as  a  negative  quantity  are  found,  1  and  6".*  Added  to  arbitrary  mul- 
tiples of  their  abraders,  double  for  example  so  as  the  quotient  may  be  affirm- 
ative, the  multiplier  and  quotient  are  7  and  4.t     So  in  every  [similar]  case. 

Or,  statement  for  the  second  rule :     Dividends     Additive 

Divisor     3       abraded  2.;|: 

The  multiplier  and  quotient  hence  found  as  before  are  2  and  4.  These  sub- 
tiacted  from  their  respective  divisors,  give  ]  and  1 ;  as  answering  to  the  sub- 
tractive  quantity.  The  quotient  obtained  in  the  abrading  of  the  additive, 
[viz.  7]  being  added  in  one  instance  and  subtracted  in  the  other,*  the  results 
are  2  and  1 1  answering  to  the  additive  quantity ;  and  1  and  6  answering  to 
the  subtractive  :  or,  to  obtain  an  affirmative  quotient,  add  to  the  latter  twice 
their  divisors,'  and  the  result  is  7  and  4. 

260.  Rule :'  If  there  be  no  additive  quantity ;  or  if  the  additive  be 
measured  by  the  divisor ;  the  multiplier  may  be  considered  as  cipher,  and 
the  quotient  as  the  additive  divided  by  the  divisor.^ 

261.  Example.  Tell  me  promptly,  mathematician,  the  multiplier  by 
which  five  being  multiplied  and  added  to  cipher,  or  added  to  sixty-five,  the 
division  by  thirteen  shall  in  both  cases  be  without  remainder. 

Statement:  Dividends  a.iv  « 
Tx-  •  ,c.  Additive  0. 
Divisor   13 

*  The  difference  between  5  and  11,  viz.  5 — 1 1=  — 6.     The  quotient  therclore  is  negative. 
+  Thus  10  (5x2)— 6=4. 

I  23,  abraded  by  the  divisor  3,  gives  the  quotient  7  and  residue  2. 

*  4+7=11  and  1—7=— 6. 

»  1  +  (3  X  2)  =7  and  — 6+(5  x  2)=4. 

*  Applicable  if  there  be  no  additive;  or  if  it  be  divisible  by  the  divisor  without  remainder. 

'  It  is  so  in  the  latter  case:  but  in  the  former  (where  the  additive  is  null)  the  quotient  is  cipher. 
— SuR.  &c.     See  Fy.-gan,  §63. 


PULVERIZER.  119 

■  There  being  no  additive,  the  multiplier  and  quotient  are  0  and  0 ;  or  1 3 
and  5  ;  or  26  and  1 0  ;  and  so  forth. 

Statement:  Dividend  5  aji-j.-  cr 
r^-  ■  .  „  Additive  65. 
Uivuor    13 

By  the  rule  (§260)  the  multiplier  and  quotient  come  out  0  and  5  ;  or  13 

and  10;  [or  26  and  15  ;]  and  so  forth. 

Rule  :*  Or,  the  dividend  and  additive  being  abraded  by  the  divisor,  the 
multiplier  may  thence  be  found  as  before ;  and  the  quotient  from  it,  by  mul- 
tiplying the  dividend,  adding  the  additive,  and  dividing  by  the  divisor. 

In  the  former  example  (§  253)  the  reduced  dividend,  divisor  and  additive 

furnish  this  statement :   Dividend  17      a  jr..-       e 

T\-   ■  ,'      Additive  5. 

Divisor      15 

Abraded  by  the  divisor  (15)  the  additive  and  dividend  become  5  and  2;  and 

the  statement  now  is  Dividend  2      a  jj-*-       c 

Divisor    15 

Proceeding  as  before  the  two  terms  found  are    5     The  lower  one,  abraded 

35 

by  the  divisor  (15),  gives  the  multiplier  5.     Whence,  by  multiplying  with  it 

the  dividend  (17)  and  adding  (the  additive)  and  dividing  (by  the  divisor),  the 

quotient  comes  out  6. 

262.  Rule  for  finding  divers  multipliers  and  quotients  in  every  case : 
half  a  stanza.  The  multiplier  and  quotient,  being  added  to  their  respective 
[abrading]  divisors  multiplied  by  assumed  numbers,  become  manifold.'' 

The  influence  and  operation  of  this  rule  have  been  already  shown  in  va- 
rious instances. 

263.  Rule  for  a  constant  pulverizer  :'  two  half  stanzas.  Unity  being 
taken  for  the  additive  quantity,  or  for  the  subtractive,  the  multiplier  and 
quotient,  which  may  be  thence  deduced,  being  severally  multiplied  by  an 

This  is  found  in  one  copy  of  the  text;  and  is  expounded  by  a  single  commentator  Ganga'd'- 
hara;  but  unnoticed  by  the  rest.  It  occurs,  however,  in  the  similar  chapter  of  the  Vija-ganita, 
§62. 

»  See  Vij.-gan.  §  64. 

'  St'hira-cuUaca,  steady  pulverizer.  See  explanation  of  the  term  in  the  commentary  on  Brah- 
M  egupta's  algebra.— Bra^TO.  ch.  ]8,  SO — 11.  Drt'dha-cul't'aca  is  there  used  as  a  synonymous 
term. 


120  LI'LA'VATI'.  Chapter  XII. 

arbitrary'  additive  or  subtractive,  and  abraded  by  the  respective  divisors,  will 
be  the  multiplier  and  quotient  for  such  assumed  quantity.* 

In  the  first  example  (§  253)  the  reduced  dividend  and  divisor  with  addi- 
tive unity  furnish  this  statement :    Dividend  17      *  i  i  ..•      , 
''  i-\-  ■    .      1  e     Additive  1. 

Divisor      15 

Here  the  multiplier  and  quotient  (found  in  the  usual  manner)  are  7  and  8. 
These,  multiplied  by  an  assumed  additive  five,  and  abraded  by  the  respective 
divisois(15  and  17),  give  the  multiplier  and  quotient  5  and  6,  for  that  additive. 

Next  unity  being  the  subtractive  quantity,  the  multiplier  and  quotient 
thence  deduced  are  8  and  9.  These,  multiplied  by  five  and  abraded  by  the 
respective  divisors,  give  10  and  11. 

So  in  every  [similar]  case.* 

Of  this  method  of  investigation  great  use  is  made  in  the  computation  of 
planets.'     On  that  account  something  is  here  said  [by  way  of  instance.] 

264.  A  stanza  and  a  half.  Let  the  remainder  of  seconds  be  made  the 
subtractive  quantity,*  sixty  the  dividend,  and  terrestrial  days'  the  divisor. 
The  quotient  deduced  therefrom  will  be  the  seconds;  and  the  multiplier 
will  be  the  remainder  of  minutes.  From  this  again  the  minutes  and  re- 
mainder of  degrees  are  found  :  and  so  on  upwards.*  In  like  manner,  from 
the  remainder  of  exceeding  months  and  deficient  days,^  may  be  found  the 
solar  and  lunar  days. 

The  finding  of  [the  place  of]  the  planet  and  the  elapsed  days,  from  the 
remainder  of  secqnds  in  the  planet's  place,  is  thus  shown.  It  is  as  follows. 
Sixty  is  there  made  the  dividend  ;  terrestrial  days,    the  divisor ;  and  the  re- 


"  See  Vij.-gari.  §  71. 

*  See  Goldd'hyaya. 

'  See  Brahmegupta,  cb.  18,  §  9 — 12. 

♦  The  present  rule  is  for  finding  a  planet's  place  and  the  elapsed  time,  when  the  fraction  above 
seconds  is  alone  given.  Gan. 

'  The  number  of  terrestrial  days  (nycthemera)  in  a  calpa  is  stated  at  1577916450000.  6'tr»- 
tnani,  coraputation  of  planets,  ch.  1,  §  20 — 21. 

'  The  dividend  varies,  when  the  question  ascends  above  the  sexagesimal  scale,  to  signs,  revo- 
lutions, &c. 

'  Ad'hi-m6sa,  additive  months ;  and  Avatna  (or  Cshayct)  dina,  subtractive  days.  See  SirSmtuii  on 
planets,  ch.  1,  §42,  The  exceeding  months,  or  more  lunar  than  solar  months,  in  a  calpa,  are 
.15933QOCX)0.    The  deficient  days  or/eai<rr  terrestrial  days  than  lunar,  in  a  calpa,  are  25082550000. 


CONSTANT    PULVERIZER. 


121 


mainder  of  seconds,  the  subtractive  quantity :  with  which  the  multiplier 
and  quotient  are  to  be  found.  The  quotient  will  be  seconds;  and  the  mul- 
tiplier the  remainder  of  minutes.  From  this  remainder  of  minutes  taken 
[as  the  subtractive  quantity]  the  quotient  deduced  will  be  minutes;  and  the 
multiplier,  the  remainder  of  degrees.  The  residue  of  degrees  is  next  the 
subtractive  quantity;  terrestrial  days,  the  divisor;  and  thirty,  the  dividend: 
the  quotient  will  be  degrees  ;  and  the  multiplier,  the  remainder  of  signs. 
Then  twelve  is  made  the  dividend ;  terrestrial  days,  the  divisor ;  and  the  re- 
mainder of  signs,  the  subtractive  quantity  :  the  quotient  will  be  signs  ;  and 
the  multiplier,  the  remainder  of  revolutions.  Lastly,  the  revolutions  in  a 
calpa  become  the  dividend ;  terrestrial  days,  the  divisor ;  and  the  remainder 
of  revolutions,  the  subtractive  quantity  :  the  quotient  will  be  the  elapsed 
revolutions;  and  the  multiplier,  the  number  of  elapsed  days.*  Examples  of 
this  occur  [in  the  Siroma/ii]  in  the  chapter  of  the  problems.* 

Li  like  manner  the  exceeding  months  in  a  calpa  are  made  the  dividend  ; 
solar  days,  the  divisor ;'  and  the  remainder  of  exceeding  months,  the  sub- 
tractive  quantity  :  the  quotient  will  be  the  elapsed  additional  months;  and 
the  multiplier,  the  elapsed  solar  days.  So  the  deficient  days  in  a  calpa  are 
made  the  dividend ;  lunar  days,  the  divisor  ;*  and  the  remainder  of  deficient 
days,  the  subtractive  quantity  :  the  quotient  will  be  the  elapsed  fewer  days; 
and  the  multiplier,  the  elapsed  lunar  days.' 


'  The  elapsed  days  of  the  calpa  to  the  time  for  which  the  planet's  place  is  found.  The  method 
of  computing  elapsed  days  to  any  given  time  is  taught  in  the  Siromarii  on  planets,  ch.  1,  §  47—49. 

*  Tri-pramad'hi/aya.     Also  in  the  G6ld'd'hi//iya,  and  Mad'liyagrah£d'hi)6ya.  Gang. 

'  The  solar  days,  each  equal  to  the  sun's  passage  through  one  degree  of  its  annual  revolution, 
are  1555200000000  in  the  calpa.     SeeSiromani  1,  §  40. 

♦  The  lunar  days,  reckoning  thirty  to  the  month  or  synodical  revolution,  are  1602999OOOOOO  in 
the  calpa.     See  Sirumaiii  1 ,  §  40. 

'  These  may  be  illustrated,  as  the  preceding  astronomical  example  is,  and  rendered  distinctly 
intelligible,  by  instances  given  by  the  commentators  Ganga'd'haba  and  Gan'e's'a,  and  the  Manu- 
runjana,  in  arbitrary  numbers.  Put  the  terrestrial  days  in  a  calpa  19,  the  revolutions  of  the 
planet  10,  the  elapsed  days  12.  Then,  by  the  proportion  I9  |  10  |  12  |  the  planet's  place  comes 
out  in  revolutions,  signs,  &c.  6' 3*  23"  41' 3"-^g.  In  bringing  out  the  seconds,  the  remainder  of 
seconds  is  3.  From  this,  by  an  inverse  process,  the  planet's  place  is  10  be  found.  Here  the  re- 
mainder of  seconds  is  the  subtractive  quantity  3;  the  dividend  is  60;  and  the  divisor,  IQ.  Pro- 
ceeding as  directed  (§256)  the  multiplier  and  quotientare  found  lands.  The  quotient  is  the  number 
of  seconds  3  ;  and  the  multiplier  is  the  remainder  of  minutes  1.  Let  this  be  the  subtractive  quan- 
tity, 1 ;  the  dividend  6O;  and  the  divisor,  19.     Proceeding  as  directed,  the  multiplier  and  quotient 

K 


122  LI'LA'VATI'.  Chapter  XII. 

265.  Rule  for  a  conjunct  pulverizer.'  If  the  divisor  be  the  same  and 
the  multipliers  various;*  then,  making  the  sum  of  those  multipliers  tlie  di- 
vidend, and  the  sum  of  the  remainders  a  single  remainder,  and  applying  the 
foregoing  method  of  investigation,  the  precise  multiplier  so  found  is  deno- 
minated a  conjunct  one. 

266.  Example.  What  quantity  is  it,  which  multiplied  by  five,  and  di- 
vided by  sixty-three;  gives  a  residue  of  seven  ;  and  the  same  multiplied  by 
ten  and  divided  by  sixty-three,  a  remainder  of  fourteen?  declare  the 
number.' 

Here  the  sum  of  the  multipliers  is  made  the  dividend  ;  and  the  sum  of  the 

residues,   a  subtractive  quantity;  and  the  statement  is  Dividend  15     g  i 

Divisor     63 

tractive  21.     Or  reduced  to  least  terms  Dividend  5     Subtractive  7 

Divisor   21 

Proceeding  as  before,  the  multiplier  is  found  14.* 

are  found  13  and  41.  The  minutes  are  therefore  41  ;  and  the  remainder  of  degrees  13.  This  again 
being  the  subtractive  quantity,  13;  the  dividend,  30;  and  the  divisor,  19;  the  multiplier  and 
quotient  are  15  and  23.  The  degrees  then  are  23;  and  the  remainder  of  signs  15.  The  subtractive 
quantity  then  being  15;  thedividend  12;  and  the  divisor  19  ;  the  multiplier  and  quotient  are  6  and  3. 
Thus  the  signs  are  3  ;  and  the  remainder  of  revolutions  6.  This  becomes  the  subtractive  quanti- 
ty, 6;  the  dividend,  10;  and  divisor,  19;  whence  the  multiplier  and  quotient  come  out  12  and  6. 
The  revolutions  therefore  are  6;  and  the  elapsed  time  is  12.  Gang.    Gan.  &c. 

'  Sanslishia-cuitaca  or  sansHshia-sphuta-cuttaca,  a  distinct  pulverizing  multiplier  belonging  to 
conjunct  residues. — Gan.  A  multiplier  ('euWacaJ  consequent  on  conjunction ;  one  deduced  from 
the  sum  of  multipliers  and  that  of  remainders.  Su  r. 

*  Whether  two,  three  or  more.— Gan.  on  Lil.  and  Crishn.  on  ViJ. 

'  See  another  example  in  the  GolffcChy&ya  or  spherics  of  the  astronomical  portion  of  the  Siromani. 

Gan.  and  Cri'shn. 

*  The  quotient  as  it  comes  out  in  this  operation  is  not  to  be  taken  :  but  it  is  to  be  separately 
sought  with  the  several  original  multipliers  applied  to  this  quantity  and  divided  by  the  divisor  as 
given.  Gak. 


T*     . 


CHAPTER    XIII. 


COMBINATION} 

9,67-  Rule  The  product  of  multiplication  of  the  arithmetical  series 
beginning  and  increasing  by  unity  and  continued  to  the  number  of  places, 
will  be  the  variations  of  number  with  specific  figures:  that,  divided  by  the 
number  of  digits  and  multiplied  by  the  sum  of  the  figures,  being  repeated 
in  the  places  of  figures  and  added  together,  will  be  the  sum  of  the  permu- 
tations. 

268.  Example.  How  many  variations  of  number  can  there  be  with  two 
and  eight?  or  with  three,  nine  and  eight?  or  with  the  continued  series  from 
two  to  nine  ?  and  tell  promptly  the  several  sums  of  their  numbers. 

Statement  1st  Example:     2.  8. 

Here  the  number  of  places  is  2.  Tlie  product  of  the  series  from  1  to  the 
number  of  places  and  increasing  by  unity,  (1,  2.)  will  be  2.  Thus  the  permu- 
tations of  number  are  found  2. 

That  product  2,  multiplied  by  the  sum  of  the  figures,   10  [2  and  8]  is  20; 

and  divided  by  the  number  of  digits  2,  is  10.     This,  repeated  in  the  places  of 

figures  [10      and  added  together,  is  110;  the  sum  of  the  numbers. 
10] 

Statement  2d  Example  :     3.  9.  8. 

The  arithmetical  series  is  1.  2.  3 ;  of  which  the  product  is  6;  and  so  many 


'  Anca-f&ia-vyavah&ra  or  Anca-p&sd'd'kydya,  concatenation  of  digits :  a  mutual  mixing  of  the 
numbers,  as  it  were  a  rope  or  halter  of  numerals :  their  variations  being  likened  to  a  coil.  See 
Gan.  and  Sue. 

The  subject  is  more  fully  treated  in  the  Ganitorcaumudi  of  Naeayan a  Pan'dita. 
To  find  the  number  of  the  permutations  and  the  sum  or  amount  of  them,  with  specific  num- 
bers. Gan.  and  Sua. 

b3 


124  LI'LA'VAXr.  Chapter  XIII. 

are  the  variations  of  number.     That,  multiplied  by  the  sum  20,   is   120; 

which,  divided  by  the  number  of  digits  3,  gives  40 ;  and  this,  repeated  in 

the  places  of  figures  [40  and  summed,    makes  4440  the  sum   of  the 

40 
40] 

numbers. 

Statement  3d  Example :     2.  3.  4.  5. 6.  7.  8.  P. 

The  arithmetical  series  beginning  and  increasing  by  unity  is  1.  2.  3.  4. 5.  6. 
7.  8.  The  product  gives  the  permutation  of  numbers  40320.  This,  multi- 
plied by  the  sum  of  the  figures  44,  is  1774080;  and  divided  by  the  number 
of  terms  8,  is  221760;  and  the  quotient  being  repeated  in  the  eight  places 
of  figures  and  summed,  the  total  is  the  sum  of  the  numbers  2463999935360. 

269.  Example.  How  many  are  the  variations  of  form  of  the  god 
Sambhu  by  the  exchange  of  his  ten  attributes  held  reciprocally  in  his  seve- 
ral hands  :  namely  the  rope,  the  elephant's  hook,  the  serpent,  the  tabor,  the 
skull,  the  trident,  the  bedstead,  the  dagger,  the  arrow,  and  the  bow :'  as 
those  of  Hari  by  the  exchange  of  the  mace,  the  discus,  the  lotus  and  the 
conch  ? 

Statement:     Number  of  places  10. 

In  the  same  mode,  as  above  shown,  the  variations  of  form  are  found 
3628800. 

So  the  variations  of  form  of  IIari  are  24. 

'  Sambhu  or  Siva  is  represented  with  ten  arms,  and  holding  in  his  ten  hands  the  ten  weapons 
or  symbols  here  specified ;  and,  by  changing  the  several  attributes  from  or»e  hand  to  another,  a 
variation  may  be  efl'ected  in  the  representation  of  the  idol  :  in  the  same  manner  as  the  image  of 
Hari  or  Vishnu  is  varied  by  the  exchange  of  his  four  symbols  in  his  four  hands.  The  twenty- 
four  different  representations  of  VishnV,  arising  from  this  diversity  in  the  manner  of  placing  the 
weapons  or  attributes  in  his  four  hands,  are  distinguished  by  as  many  discriminative  titles  of  the 
god  allotted  to  those  figures  in  the  tlieogonies  or  I'urd/ias.  It  does  not  appear  that  distinct  titles 
have  been  in  like  manner  assigned  to  any  part  of  the  more  than  three  millions  of  varied  represen- 
tations of  Siva. 

The  ten  attributes  of  Siva  are,  \st,  pdsa,  a  rope  or  chain  for  binding  an  elephant ;  2d,  ancusa,  a 
hook  for  guiding  an  elephant ;  3(1,  a  serpent;  4th,  Wamaru,  a  tabor;  5tli,  a  human  skull;  6th,  a 
trident;  7th,  c'/iaftvdnga,  a  bedstead,  or  a  club  in  form  of  the  foot  of  one;  8th,  a  dagger;  9tb,  an 
arrow  ;  lOlh,  a  bow. 


COMBINATION. 


125 


270.  Rule  :*  The  peiinutations  found  as  before,  being  divided  by  the 
combinations  separately  computed  for  as  many  places  as  are  filled  by  like 
fligits,  will  be  the  variations  of  number;  from  which  the  sum  of  the  numbers 
will  be  found  as  before. 

27*1.  Example.  How  many  are  the  numbers  with  two,  two,  one  and 
one?  and  tell  me  quickly,  mathematician  their  sum:  also  with  four,  eight, 
five,  five  and  five ;  if  thou  be  conversant  with  the  rule  of  permutation  of 
numbers. 


Statement  1st  Example:     2.2.1.1. 

Here  the  peiTnutations  found  as  before  (§  267)  are  24:  First,  two  places 
are  filled  by  like  digits  (2.2.) ;  and  the  combinations  for  that  number  of  places 
are  2.  Next  two  other  places  are  filled  by  like  digits  (1.1.);  and  the  combi- 
nations for  these  places  are  also  2.  Total  4.  The  permutations  as  before 
24,  divided  by  (4)  the  twofold  combinations  for  two  pairs  of  like  digits, 
give  6  for  the  variations  of  number :  viz.  2211,2121,  2112,  1212,  1221, 
1 J22."    The  sum  of  the  numbers  is  found  as  before  9999-^ 

Statement  2d  Example :     4.8.5.5.5. 

Here  the  permutations  found  as  before  are  120 ;  which,  divided  by  the 
combinations  for  three  places  6^,  give  the  variations  20:  viz.  48555,  84555, 
54855,  58455.  55485,  55845,  55548,  55584,  45855,  45585,  45558,  85455, 
85545,  85554,  54585,  58545,  55458,  55854,  54558,  58554. 

The  sum  of  the  numbers  comes  out  1 199988.* 

27i-  Rule  :*  half  a  stanza.  The  series  of  the  numbers  decreasing  by 
unity  from  the  last*  to  the  number  of  places,  being  multiplied  together,  will 
be  the  variations  of  number,  withdissin)ilar  digits. 

'  Special ;  being  applicable  when  two  or  more  of  the  digits  are  alike. 

*  The  enumeration  of  the  possible  combinations  is  termed  prastdra. 

'  The  variations  6,  multiplied  by  the  sum  of  the  figures  6,  and  divided  by  the  number  of  digits 
4,  give  9 ;  which  being  repeated  in  four  places  of  figures  and  summed  makes  9999- 

*  Variations  20,  multiplied  by  the  sum  of  the  figures  27,  give  540 ;  which,  divided  by  the  num- 
ber of  digits  5,  makes  108  :  and  this  being  repeated  in  five  places  of  figures  and  summed,  yields 
11999^8. 

*  To  find  the  variations  for  a  definite  number  of  places  with  indeterminate  digits.  Gan. 

*  That  is,  from  nine.  -  Gan.  &c. 


126  LI'LAVATI'.  Chapter  XIII. 

273.  Example.  How  many  are  the  variations  of  number  with  any  digits 
except  cipher  exchanged  in  six  places  of  figures  ?  If  thou  know,  declare 
them. 

The  last  number  is  nine.  Decreasing  by  unity,  for  as  many  as  are  the 
places  of  figures,  the  statement  of  the  series  is  9-  8.  7-  6.  5. 4.  The  product 
of  these  is  d0480.» 

fi74.  Rule  :*  a  stanza  and  a  half.  If  the  sum  of  the  digits  be  determi- 
nate, the  arithmetical  series  of  numbers  from  one  less  than  the  sum  of  the 
digits,  decreasing  by  unity,  and  continued  to  one  less  than  the  places,  being 
divided  by  one  and  so  forth,  and  the  quotients  being  multiplied  together,  the 
product  will  be  equal  to  the  variations  of  the  number. 

This  rule  must  be  understood  to  hold  good,  provided  the  sum  of  the  digits 
be  less  than  the  number  of  places  added  to  nine. 

A  compendium  only  has  been  here  delivered  for  fear  of  prolixity:  since 
the  ocean  of  calculation  has  no  bounds. 

275.  Example.  How  many  various  numbers  are  there,  with  digits 
standing  in  five  places,  the  sum  of  which  is  thirteen  ?  If  thou  know,  de- 
clare them. 

Here  the  sum  of  the  digits  less  one  is  12.  The  decreasing  series  from 
this  to  one  less  than  the  number  of  digits,  divided  by  unity,  &c.  being  exhi- 
bited, the  statement  is  y  y  »/  l-  The  product  of  their  multiplication 
[^■~^]  is  equal  to  the  variations  of  the  number,  495.' 

276.  Though  neither  multiplier,  nor  divisor,  be  asked,  nor  square,  nor 
cube,  still  presumptuous  inexpert  scholars  in  arithmetic  will  assuredly  fail 
in  [problems  on]  this  combination  of  numbers. 

»  The  combinations  of  two  dissimilar  digits,  excluding  cipher,  are  72 ;  with  three,  504;  with 
/our,  3024;  with  five,  15120;  with  six  60480. 

*  To  fmd  the  combinations  with  indeterminate  digits  for  a  definite  sum  and  a  specific  number 
of  places.  Gan. 

'  9U11,  52222,  13333;  each  five  ways.  55111,  22333;  each  ten  ways.  82111,  73111, 
64111,  43222,  61222;  each  twenty  ways.  72211,  53311,  44221,  44311;  each  thirty  ways. 
6321 1,  54211,  53221,  43321  ;  each  sixty  ways.    Total  four  hundred  and  ninety-five. 


COMBINATION. 


127 


277-  Joy  and  happiness  is  indeed  ever  increasing  in  this  world  for  those 
who  have  Lildvatl  clasped  to  their  throats,*  decorated  as  the  members  are 
with  neat  reduction  of  fractions,  multiplication  and  involution,  pure  and 
perfect  as  are  the  solutions,  and  tasteful  as  is  the  speech  which  is  exem- 
plified. 


'  By  constant  repetition  of  the  text.  This  stanza,  ambiguously  expressed  and  bearing  a  double 
import,  implies  a  simile :  as  a  charming  woman  closely  embraced,  whose  person  is  embellished 
by  an  assemblage  of  elegant  qualities,  who  is  pure  and  perfect  in  her  conduct,  and  who  utters 
agreeable  discourse.     SeeGAN. 


VtJA-GANlTA, 


OR 


AVYA  CT  AG  ANITA; 

ELEMENTAL   ARITHMETIC   OR  ALGEBRA. 


CHAPTER  I. 

ALGORITHM   or   LOGISTICS: 


SECTION  I. 

INVOCATION  and  INTRODUCTION. 

1.  I  REVEKE  the  unapparent  primary  matter,  which  the  Sane' hyas^  de- 
clare to  be  productive  of  the  intelligent  principle,  being  directed  to  that 
production  by  the  sentient  being :  for  it  is  the  sole  element  of  all  which  is 
apparent.     I  adore  the  ruling  power,  which  sages  conversant  with  the  nature 

'  Paricarma-trituati ;  thirty  operations  or  modes  of  process.     Lild.  c.  2,  §2. 

*  Not  the  followers  of  Capila,  but  those  of  Pa'tanjali.  The  same  term  Sinc'hya,  as  relating  to 
another  member  of  the  period,  signifies  sages  conversant  with  theology  and  the  nature  of 
soul;  and,  corresponding  again  to  another  member  of  it,  the  same  word  intends  calculators  and 
mathematicians,  whose  business  is  with  Sanc'hi/d  number.  Throughout  the  stanza  the  same  words 
are  employed  in  threefold  acceptations :  and,  in  translating  it,  the  distinct  meanings  are  repeated 
in  separate  members  of  a  period  :  because  the  ambiguity  of  the  original  could  not  be  preserved  by 
a  version  of  it  as  of  a  single  sentence. 


ISO  VI'JA-GAN'ITA.  Chapter  I. 

of  soul  pronounce  to  be  the  cause  of  knowledge,  being  so  explained  by  a 
holy  person  :  for  it  is  the  one  element  of  all  which  is  apparent.  I  venerate 
that  unapparent  computation,  which  calculators  affirm  to  be  the  means  of 
comprehension,  being  expounded  by  a  fit  person  :  for  it  is  the  single  element 
of  all  which  is  apparent. 

2.  Since  the  arithmetic  of  apparent  [or  known]  quantity,  which  hax 
been  already  propounded  in  a  former  treatise,  is  founded  on  that  of  unap- 
parent [or  unknown]  quantity  ;  and  since  questions  to  be  solved  can  hardly 
be  understood  by  any,  and  not  at  all  by  such  as  have  dull  apprehensions, 
without  the  application  of  unapparent  quantity ;  therefore  I  now  propound 
the  operations  of  analysis.* 

'  Fya  cause,  origin;  primary  cause  (&di-cdrana). — Su'r.  Hence  signifying  in  mathematics, 
analysis,  algebra. 

Vija-criyA :  operation  of  analysis ;  elemental  or  algebraic  solution.  See  explanation  of  the  title 
o{  Vija-ganita,  causal  or  elemental  arilbmetic,  ch.  7,  §174. 


(     131     ) 


SECTION  II. 

Logistics  of  Negative  and  Affirmative  Quantities. 

ADDITION. 

3.  Rule  for  addition  of  affirmative  and  negative  quantities :  half  a  stanza. 
In  the  addition  of  two  negative  or  two  affirmative'  quantities,  the  sum  must 
be  taken :  but  the  difference  of  an  affirmative  and  a  negative  quantity  is 
their  addition.^ 

4.  Example.  Tell  quickly  the  result  of  the  numbers  three  and  four, 
negative  or  affirmative,  taken  together :  that  is,  affirmative  and  negative,  or 
both  negative  or  both  affirmative,  as  separate  instances :  if  thou  know  the 
addition  of  affirmative  and  negative  quantities. 

The  characters,  denoting  the  quantities  known  and  unknown,'  should  be 
first  written  to  indicate  them  generally ;  and  those,  which  become  negative, 
should  be  then  marked  with  a  dot  over  them. 

Statement :     3.  4.     Adding  them,  the  sum  is  found  7. 

Statement:     3. 4.     Adding  them,  the  sum  is  7. 

Statement:  3.4.  Taking  the  difference,  the  result  of  addition  comes 
out  i. 


'  Riiia  or  cshaya,  minus  ;  literally  debt  or  loss :  negative  quantity, 
D'hana  or  swa,  plus  ;  literally  wealth  or  property  :  affirmative  or  positive  quantity. 
For  a  demonstration  of  the  rule,  the  commentators,  Su'rtada'sa  and  Crishn'a,  exhibit  fami- 
liar examples  of  the  comparison  of  debts  and  assets. 

*  Rdsi,  quantity,  is  either  vyacta,  absolute,  specifically  known,  (which  is  termed  rupa,  form, 
ipecies ;)  or  it  is  avyacta,  indistinct,  unapparent,  unknown  (ajnyAta).  It  may  either  be  a  multiple 
of  the  arithmetical  unit,  or  a  part  of  it,  or  the  unit  itself.     See  Ceishna. 

S2 


132  VI'JA-G  ANITA.  Chapter  I. 

Statement :     3.  4.     Taking  the  difference,  the  result  of  addition  is  1. 
So  in  other  instances/  and  in  fractions''  likewise. 

SUBTRACTION. 


5.  Rule  for  subtraction  of  positive  and  negative  quantities  :  half  a 
stanza.  The  quantity  to  be  subtracted  being  affirmative,  becomes  nega- 
tive ;  or,  being  negative,  becomes  affirmative :  and  the  addition  of  the  quan- 
tities is  then  made  as  above  directed.' 

6.  Example :  half  a  stanza.  Subtracting  two  from  three,  affirmative 
from  affirmative,  and  negative   from  negative,    or  the  contrary,    tell  me 

quickly  the  result. 

I 

»  For  the  addition  of  unknown  and  compound  quantfties  and  surds,  see  §  18 — 30. 

'  Whether  known  or  unknown  quantities  having  divisors.  Of  such  as  have  like  denominators, 
the  sum  or  difference  is  taken.  Else,  other  previous  operations  take  place  for  the  reduction  of 
them  to  a  common  denominator.     The  same  must  be  understood  in  subtraction.  CniSHN. 

'  In  demonstrating  this  rule,  the  commentator  Crishn'a  bhatta  observes,  that '  here  negation 
is  of  three  sorts,  according  to  place,  time,  and  things.  It  is,  in  short,  contrariety.  Wherefore  the 
LiMvati,  §  166,  expresses  "  The  segment  is  negative,  that  is  to  say,  is  in  the  contrary  direction." 
As  the  v^est  is  the  contrary  of  east ;  and  the  south  the  converse  of  north.  Thus,  of  two  countries, 
east  and  west,  if  one  be  taken  as  positive,  the  other  is  relatively  negative.  So  when  motion  to  the 
cast  is  assumed  to  be  positive,  if  a  planet's  motion  be  westward,  then  the  number  of  degrees  equiva- 
lent to  the  planet's  motion  is  negative.  In  like  manner,  if  a  revolution  westward  be  affirmative,  so 
much  as  a  planet  moves  eastward,  is  in  respect  of  a  western  revolution  negative.  The  same  may 
be  understood  in  regard  to  south  and  north,  &c.  That  prior  and  siiljsequent  times  are  relatively 
to  each  other  negative,  is  familiarly  understood  in  reckoning  of  days.  So  in  respect  of  chattels, 
that,  to  which  a  man  bears  the  relation  of  owner,  is  considered  as  positive  in  regard  to  him  :  and 
the  converse  [or  negative  quantity]  is  that  to  which  another  person  has  the  relation  of  owner. 
Hence  so  much  as  belongs  to  Yqjnyadatta  m  the  wealth  possessed  by  Devadatta,  is  negative  in 
respect  of  Devadatta.  The  commentator  gives  us  an  example  the  situation  of  Pattana  (Patna) 
and  Praydga  (AUahibdd)  relatively  to  Ananda-vana  (Benares).  Pattana  on  the  Ganges  bears  east 
of  VMriasi,  distant  fifteen  yojanas  ;  and  Praydga  on  the  confluence  of  the  Gangd  and  Yamvnd, 
bears  west  of  the  same,  distant  eight  yojanas.  The  interval  or  difference  is  twenty-three  yojanas; 
and  is  not  obtained  but  by  addition  of  the  numbers.  Therefore,  if  the  difference  between  two 
contrary  quantities  be  required,  their  sura  must  be  taken.  Crishw. 


Section  II. 


LOGISTICS. 


133 


Statement:  3.2.  The  subtrahend,  being  affirmative,  becomes  negative; 
and  the  result  is  1 . 

Statement :  3.  2.  The  negative  subtrahend  becomes  affirmative ;  and 
the  result  is  1.  •       , 

Statement:  3.  2.  The  negative  subtrahend  becomes  affirmative;  and 
the  result  is  5. 

Statement :  3.  2.  The  affirmative  subtrahend  becomes  negative ;  and 
the  result  is  5. 

MULTIPLICATION. 

7.  Rule  for  multiplication  [and  division]  of  positive  and  negative  quan- 
tities :  half  a  stanza.  The  product  of  two  quantities  both  affirmative,  is  po- 
sitive.* When  a  positive  quantity  and  a  negative  one  are  multiplied  toge- 
ther, the  product  is  negative.*     The  same  is  the  case  in  division. 

'  The  sign  only  of  the  product  is  taught.  All  the  operations  upon  the  numbers  are  the  same 
which  were  shown  in  simple  arithmetic  {LUa.  §  14 — 16).  Crishn. 

*  Multiplication,  as  explained  by  the  commentators,*  is  a  sort  of  addition  resting  on  repetition 
of  the  multiplicand  as  manj'  times  as  is  the  number  of  the  multiplicator.  Now  a  multiplicator  is 
of  two  sorts,  positive  or  negative.  If  it  be  positive,  the  repetition  of  the  multiplicand,  which  is 
affirmative  or  negative,  will  give  correspondently  an  affirmative  or  negative  product.  The  multi- 
plication then  of  positive  quantities  is  positive ;  and  that  of  a  negative  multiplicand  by  a  positive 
multiplier  is  negative  :  as  is  plain.  The  question  for  disquisition  concerns  a  negative  multiplier. 
It  has  been  before  observed  that  negation  is  contrariety.  A  negative  multiplier,  therefore,  is  a 
contrary  one :  that  is,  it  makes  a  contrary  repetition  of  the  multiplicand.  Such  being  the  case, 
if  the  multiplicand  be  positive,  (the  multiplier  being  negative),  the  product  will  be  negative  ;  if  the 
multiplicand  be  negative,  the  product  will  be  affirmative.  In  the  latter  case  the  multiplication 
of  two  negative  quantities  gives  an  affirmative  product.  In  the  middle  instances,  either  of  the  two 
(multiplicator  or  multiplicand)  being  positive,  and  the  other  negative,  the  product  is  negative:  as 
is  taught  in  the  text. 

Or  the  proof  may  be  deduced  from  the  process  of  computation.  There  is  no  dispute  respecting 
the  multiplication  of  affirmative  quantities:  but  the  discussion  arises  on  that  of  negative  quantity. 
Now  so  much  at  least  is  known  and  admitted,  that,  the  multiplicand  being  separately  multiplied 
by  component  parts  of  the  multiplier,  and  the  products  added  together,  the  sum  is  the  product  of 
the  proposed  multiplication.  Let  the  multiplicand  be  135,  and  the  multiplicator  12  ;  and  its  two 
parts,  (the  one  arbitrarily  assumed,  the  other  equal  to  the  given  number  less  the  assumed  one,) 

*  SvnuADASi  on  Lildvad.    Ganesa  on  the  same.    Cbishna-bhatta  on  Vija-ganita, 


184  Vl'JA-GAN'ITA.  ChapteeI. 

8.  Example :  half  a  stanza  (completing  §  g).  What  is  the  product  of 
two  multiplied  by  three,  positive  by  positive;  and  negative  by  negative;  or 
positive  by  negative  ? 

Statement:  2.  3.  Affirmative  multiplied  by  affirmative  is  affirmative. 
Product  6. 

Statement:  2.  3.  Negative  multiplied  by  negative  is  positive.  Pro- 
duct 6. 

Statement :  2.  3.  [or  2.  3.]  Positive  multiplied  by  negative  [or,  negative 
by  positive]  is  negative.     Product  6. 

The  result  is  the  same,  if  the  multiplicator  be  multiplied  by  the  multipli- 
cand.^ 


DIVISION. 

Rule.    The  same  is  the  case  in  division  (§  7).* 

9.  Example.  The  number  eight  being  divided  by  four,  affirmative  by 
affirmative,  negative  by  negative,  positive  by  negative,  or  negative  by  po- 
sitive, tell  me  quickly,  what  is  the  quotient,  if  thou  well  know  the  method. 

4  and  8.  Then  the  multiplicand  being  separately  multiplied  by  those  component  parts  of  the 
multiplicator,  give  540  and  1080:  which,  added  together,  make  the  product  lC20.  In  like 
manner  let  the  assumed  portion  be  4.  The  other,  (or  given  number  less  that)  will  be  l6.  Here 
also,  if  die  multiplicand  be  separately  multiplied  by  those  parts,  and  the  products  added  together, 
the  same  aggregate  product  should  be  obtained.  But  the  multiplicand,  multiplied  severally  by 
those  parts,  gives  540  and  2l6o.  The  sum  of  these  numbers  [with  the  same  signs]  does  not  agree 
with  the  product  of  multiplication.  It  follows  therefore,  since  the  right  product  is  not  otherwise 
obtained,  that  the  multiplication  of  a  positive  and  a  negative  quantity  together  give  a  negative 
result.  For  so  the  addition  of  540  and  2l6'0  [with  contrary  signs]  makes  the  product  right :  vi«. 
1620.  Crishn. 

"  It  is  thus  intimated,  that  either  quantity  may  at  pleasure  be  treated  as  multiplicator,  and  the 
other  as  multiplicand  :  and  conversely.  Crishv. 

*  If  both  the  dividend  and  the  divisor  be  affirmative,  or  both  negative,  the  quotient  is  afhrm- 
ative:  but,  if  one  be  positive  and  the  other  negative,  the  quotient  is  negative.  Crishn. 


Section  II.  LOGISTICS.  135 

Statement :  8.  4.  Affirmative  divided  by  affirmative  gives  an  affirmative 
quotient  2. 

Statement:  8.  4.  Negative  by  negative  gives  an  affirmative  quotient  2. 

Statement :  8.  4.  Positive  by  negative  gives  a  negative  quotient  2. 

Statement :  8.  4.  Negative  by  positive  gives  a  negative  quotient  2. 


SQUARE  AND  SQUARE-ROOT. 

10.  Rule  :  half  a  stanza.  Tlie  square  of  an  affirmative  or  of  a  negative 
quantity  is  affirmative ;  and  the  root  of  an  affirmative  quantity  is  two-fold, 
positive  and  negative.  There  is  no  square-root  of  a  negative  quantity  :  for 
it  is  not  a  square.^ 

11.  Example.  Tell  me  quickly,  friend,  what  is  the  square  of  the  num- 
ber three  positive ;  and  of  the  same  negative?  Say  promptly  likewise  what 
is  the  root  of  nine  affirmative  and  negative,  respectively? 

Statement :     3.  3.     Answer  :  the  squares  come  out  9  and  Q. 

Statement :     9.     Answer :  the  root  is  3  or  3. 

Statement :     9.     Answer :  there  is  no  root,  since  it  is  no  square. 

'  For,  if  it  be  maintained,  that  a  negative  quantity  may  be  a  square,  it  must  be  shown  what  it 
can  be  a  square  of.  Now  it  cannot  be  the  square  of  an  affirmative  quantity  :  for  a  square  is  the 
product  of  the  multiplication  of  two  like  quantities ;  and,  if  an  affirmative  one  be  multiplied  by  an 
affirmative,  the  product  is  affirmative.  Nor  can  it  be  the  square  of  a  negative  quantity  :  for  a  ne- 
gative quantity  also,  multiplied  by  a  negative  one,  is  positive.  Therefore  we  do  not  perceive  any 
quantity  such,  as  that  its  square  can  be  negative.  Crishn. 


(     136    ) 


SECTION  III. 


CIPHER. 

12.  Rule  for  addition  and  subtraction  of  cipher:  part  of  a  stanza.  In 
the  addition  of  cipher,  or  subtraction  of  it,  the  quantity,*  positive  or  nega- 
tive, remains  the  same.     But,  subtracted  from  cipher,  it  is  reversed.* 

13.  Example :  half  a  stanza.  Say  what  is  the  number  three,  positive,  or 
[the  same  number]  negative,  or  cipher,  added  to  cipher,  or  subtracted  from 
it?» 

Statement :  3.  3.  0.  These,  having  cipher  added  to,  or  subtracted  from, 
them,  remain  unchanged :  3.  3.  0.* 

Statement :     3.  3.  0.     Subtracted  from  cipher,  they  become  3.  3.  0.* 

'  Whether  absolute,  expressed  by  digits,  or  unknown,  denoted  by  letter,  colour,  &c.  or  an 
irrational  and  surd  root.  Cbishn. 

*  In  both  cases  of  addition,  and  in  the  first  of  subtraction,  the  absolute  number,  unknown  quan- 
tity, or  surd,  retains  its  sign,  whether  positive  or  negative.  In  the  other  case  of  subtraction,  the 
sign  is  reversed.  Crishn. 

'  Or  having  cipher  added  to,  or  subtracted  from,  it.  Crishn. 

♦  In  addition,  if  either  of  the  quantities  be  increased  or  diminished,  the  result  of  the  addition  is 
just  so  much  greater  or  less.  If  then  either  be  reduced  to  nothing,  the  other  remains  unchanged. 
But  subtraction  diminishes  the  proposed  quantity  by  so  much  as  is  the  amount  of  the  subtrahend  ; 
and,  if  the  subtrahend  be  reduced,  the  result  is  augmented  :  if  it  be  reduced  to  nought,  the  result. . 
rises  to  its  maximum  ;  the  amount  of  the  proposed  quantity.  Or,  if  the  proposed  quantity  be  itself 
reduced,  the  result  of  the  subtraction  is  diraini!>hed  accordingly  :  if  reduced  to  nought,  the  result 
is  diminished  to  its  greatest  degree  ;  the  amount  of  the  sublrahend  with  the  subtractive  sign.     See 

ClllSHN. 

'  Cipher  is  neither  positive  nor  negative :  and  it  is  therefore  exhibited  with  no  distinction  of 
sign.     No  difference  arises  from  the  reversing  of  it ;  and  none  is  here  shown.  Cuishn. 


Section  III.  LOGISTICS.  137 

14.  Rule  :  (completing  the  stanza,  §  12.)  In  the  multiplication  and  the 
rest  of  the  operations*  of  cipher,  the  product  is  cipher ;  and  so  it  is  in  mul- 
tiplication by  cipher :  but  a  quantity,  divided  by  cipher,  becomes  a  fraction 
the  denominator  of  which  is  cipher."  n  ,u  ntu ni'jio  to  xioit 


15.  Example:  half  a  stanza.  Tell  me  the  product  of  cipher  multiplied 
by  two ;'  and  the  quotient  of  it  divided  by  three,  and  of  three  divided  by 
cipher;  and  the  square  of  nought;  audits  root. 

.1) 
Statement:     Multiplicator  2.     Multiplicand 0.     Product  0.  ; „ 

[Statement :     Multiplicator  0.     Multiplicand  2.     Product  0*.] 

Statement :     Dividend  0.     Divisor  3.     Quotient  0. 

.■/ 
Statement :     Dividend  3.     Divisor  0.     Quotient  the  fraction  ^. 
This  fraction,  of  which  the  denominator  is  cipher,  is  termed  an  infinite 
quantity.' 

'  Multiplication,  division,  square  and  square-root.  Sua.  and  Crishn. 

Multiplication  and  division  are  each  two-fold:  viz.  multiplication  of  nought  by  a  quantity;  or 
the  multiplication  of  this  by  nought:  so  division  of  cipher  by  a  quantity;  and  the  division  of  this 
by  cipher.     But  square  and  square-root  are  each  single.  Crishk. 

*  The  more  the  multiplicand  is  diminished,  the  smaller  is  the  product ;  and,  if  it  be  reduced  in 
the  utmost  degree,  the  product  is  so  likewise :  now  the  utmost  diminution  of  a  quantity  is  the  same 
with  the  reduction  of  it  to  nothing :  therefore,  if  the  multiplicand  be  nought,  the  product  is  cipher. 
In  like  manner,  as  the  multiplier  decreases,  so  does  the  product;  and,  if  the  multiplier  be  nought, 
the  product  is  so  too.  In  fact  multiplication  is  repetition:  and,  if  there  be  nothing  to  be  repealed, 
what  should  the  multiplicator  repeat,  however  great  it  be  ? 

So,  if  the  dividend  be  diminished,  the  quotient  is  reduced:  and,  if  the  dividend  be  reduced  to 
nought,  the  quotient  becomes  cipher. 

As  much  as  the  divisor  is  diminished,  so  much  is  the  quotient  raised.  If  the  divisor  be  reduced 
to  the  utmost,  the  quotient  is  to  the  utmost  increased.  But,  if  it  can  be  specified,  that  the  amount 
of  the  quotient  is  so  much,  it  has  not  been  raised  to  the  utmost :  for  a  quantity  greater  than  that 
can  be  assigned.    The  quotient  therefore  is  indefinitely  great,  and  is  rightly  termed  infinite. 

Crishn. 

*  Or  else  multiplying  two.  Crishn. 
•♦  Crishk. 

'  Ananta-rdsi,  infinite  quantity.     C'ha-hara,  fraction  having  cipher  for  its  denominator. 
This  fraction,  indicating  an  infinite  quantity,  is  unaltered  by  addition  or  subtraction  of  a  finite 
quantity.    For,  in  reducing  the  quantities  to  a  common  denominator,  both  the  numerator  and 

T 


158  VI'JA-G ANITA.  Chapter  I. 

16.  In  this  quantity  consisting  of  that  which  has  cipher  for  its  divisor, 
there  is  no  alteration,  though  many  be  inserted  or  extracted ;  as  no  change 
takes  place  in  the  infinite  and  immutable  God,  at  the  period  of  the  destruc- 
tion or  creation  of  worlds,  though  numerous  orders  of  beings  are  absorbed 
or  put  forth. 

Statement:     0.     Its  square  0.     Its  root  0. 

denominator  of  the  finite  quantity,  being  multiplied  by  cipher,  become  nought :  and  a  quantity  is 
unaltered  by  the  addition  or  subtraction  of  nought.  The  numerator  of  the  infinite  fraction  may 
indeed  be  varied  by  the  addition  or  subtraction  of  a  finite  quantity,  and  so  it  may  by  that  of  another 
infinite  fraction  :  but  whether  the  finite  numerator  of  a  fraction,  whose  denominator  is  cipher,  be 
more  or  less,  the  quotient  of  its  division  by  cipher  is  alike  infinite.  Crisiin. 

This  is  illustrated  by  the  same  commentator  through  the  instance  of  the  shadow  of  a  gnomon,^ 
which  at  sunrise  and  sunset  is  infinite  ;  and  is  equally  so,  whatever  height  be  given  to  the  gnomon, 
and  whatever  numl>er  be  taken  for  radius,  though  the  expression  will  be  varied.  Thus,  if  radius 
.be  put  120;  and  the  gnomon  be  I,  2,  3,  or  4;  the  expression  deduced  from  the  proportion,  as 
sine  of  sun's  altitude  is  to  sine  of  zenith  distance  ;  so  is  gnomon  to  shadow;  becomes  LI?,  112 
3R0  Of  4jBo._  Qf^  jf  tiie  gnomon  be,  as  it  is  usually  framed,  12  fingers,  and  radius  be  taken  at 
3438,  120,  100,  Qr  90;  the  expression  will  be  ti|i*,  i*^,  LSSJi.  or  l^;  which  are  all  alik« 
infinite.     See  CafsHN. 


bttsub'ji;  •> .  . 


I 


(     139    ) 


<Sm 


SECTION  IV. 


Arithmetical  Operations  on  Unknown  Quantities. 


iJV/r.(lA 


17.  "  So  much  as"  and  the  colours  "  black,  blue,  yellow  and  red,"^  and 
others  besides  these,  have  been  selected  by  venerable  teachers  for  names  of 
values*  of  unknown  quantities,  for  the  purpose  of  reckoning  therewith.' 


18.  Rule  for  addition  and  subtraction:  Among  quantities  so  designated, 
the  sum  or  difference  of  two  or  more  which  are  alike  must  be  taken :  but 
such  as  are  unlike,*  are  to  be  separately  set  forth. 

Ani'xsaisi  oib  IbJ  hut 

19-  Example.  Say  quickly,  friend,  what  will  affirmative  one  unknown 
with  one  absolute,  and  affirmative  pair  unknown  less  eight  absolute,  make, 
if  addition  of  the  two  sets  take  place?  and  what  will  they  make,  if  the  sum 
be  taken  inverting  the  affirmative  and  negative  signs  ?' 

Statement :    ya  \    ru  \     Answer  :  the  sum  is  ya  3    ru  7. 
ya  2    ru  8 

'  Y6vat-t&vat,  correlatives,  quanlum,  tantum  ;  quot,  tot :  as  many,  or  as  much,  of  the  un- 
known, as  this  coefficient  number.     Yavat  is  relative  of  the  unknown;  and  tdvat  of  its  coefficient. 

The  initial  syllables  of  the  Sanscrit  terms  enumerated  in  the  text  are  employed  as  marks  of  un. 
known  quantities  ;  viz.  y&,  c6,  ni,  pi,  16,  (also  ha,  stce,  chi,  (sec.  for  green,  white,  variegated  and  so 
forth).  Absolute  number  is  denoted  by  ru,  initial  of  r«;)a  form,  species.  The  letters  of  the  alphabet 
are  also  used  (ch.  6),  as  likewise  the  initial  syllables  of  the  terms  for  the  particular  things  (§  11 1). 

*  Mdna,  mitt,  unmdna  or  vnmiti,  measure  or  value.     See  note  on  §  130. 

'  For  the  purpose  of  reckoning  with  unknown  quantities.  Sua.  and  Crishn. 

*  Heterogeneous  :  as  rupa,  known  or  absolute  number  :  y&vat-tuvat  (so  much  as)  the  first  un- 
known quantity,  its  square,  its  cube,  its  biquadrate,  and  the  product  of  it  and  another  factor; 
c&hca  (black)  the  second  unknown  quantity,  its  powers,  and  the  product  of  it  with  factors  :  n'daca 
(blue)  the  third  unknown,  its  powers,  and  so  forth.     See  CnfsuN. 

»  Inverting  the  signs  of  the  firstset,  of  the  second,  or  of  both,  "'  -X'"*"  ■  Crishn. 

T  S 


14b  VIJA-GANITA.  Chapter  L 

Statemcnt  (inverting  the  signs  in  the  first  set) :  ya  i    ru  i 

Answer  r    Sum  ya  I    ru  9- 

Statement  (inverting  the  signs  in  the  second  set)  :    ya  I    ru  I 

ya  S,    ru  S^ 

Answer:     Sum^a  I    ru  Q. 

Statement  (inverting  the  signs  in  both  sets)  :  ya  i     ru  l 

ya  2    ru  8 

Answer:     Sum  ya  3    ru7. 

£0.  Example.  Say  promptly  what  will  affirmative  three  square  of  aft 
unknown,  with  three  known,  be,  when  negative  pair  unknown  is  added? 
and  tell  the  remainder,  when  negative  six  unknown  with  eight  known  is- 
subtracted  from  affirmative  two  unknown. 

Statement :    yav  S    ya  0    ru  3*     Answer :     Sum  ya  v  3   yak    ru  3. 
yav  0   ya  2    ru  0 

Statement :    ya  Q    ru  O    Answer :  The  remainder  is  ya  8    ra  8. 
ya  6    ru  8 

.  .fll'.     Rule  for  multiplication  of  unknown  quantities:    two  and  a  half" 
stanzas.     When  absolute  number  and  colour  (or  letter)  arc  multiplied  one  by 
the  other,  the  product  will  be  colour  (or  letter)."     When  two,  three  or  more 

.(ii 
^  The  powers  of  the  unknown  quantity  are  thus  ordered :  first  the  highest  power,  for  e.\ample 

the  suTSolid ;  then  the  next,  the  biquadrate ;  after  it  the  cube ;  then  the  square ;  next  the  simple 

unknown  quantity ;  lastly  the  known  species.     SeeCaisHN. 

*  Multiplication  of  unknown  quantity  denoted  by  colour  (or  letter)  is  threefold  :  namely,  by 

known  or  absolute  number,  by  homogeneous  colour  or  like  quantity,  and  by  heterogeneous  colour 

or  unlike  quantity.     If  the  unknown  quantity  be  multiplied  by  absolute  number,  or  this  by  the 

mnkfiowu  quantity,  the  result  of  the  multiplication  in  figures  is  s«t  down,  and  the  denominatioo 


Section  IV. 


LOGISTICS. 


141 


homogeneous  quantities  are  multiplied  together,  the  product  will  be  the 
square,  cube  or  other  [power]  of  the  quantity.  But,  if  unlike  quantities  be 
multiplied,  the  result  is  their  (bhavita)  '  to  be'  product  or  factum.  The 
other  operations,  division  and  the  rest,'  are  here  performed  like  those  upon 
number,  as  taught  in  arithmetic  of  known  quantities. 


22.  The  multiplicand  is  to  be  set  down  in  as  many  several  places  as  there 
are  terms  in  the  multiplier,  and  to  be  successively  multiplied  by  those  terms-, 
and  the  products  to  be  added  together  b}'  the  method  above  shown."  In  this 
elemental  arithmetic  the  precept  for  multiplying  by  component  parts  of  the 
factor,  as  delivered  under  simple  arithmetic,^  must  be  understood  in  the 
multiplication  of  unknown  quantities,  of  squares,  and  of  surds, 

23.  Example.  Tell  directly,  learned  sir,  the  product  of  the  multiplica- 
tion of  the  unknown  (yavat-tdvat)  five,  less  the  absolute  number  one,  by 
the  unknown  (ydvat-tdvat)  three  joined  with  the  absolute  two:  and  also 


of  the  colour  is  retained.  The  continued  multiplication  of  like  quantities  produces,  when  two  ar« 
multiplied  together,  the  square;  when  this  is  multiplied  by  a  third  such,  the  cube;  by  a  fourth, 
the  biquadrate  ;.  by.  a  fifth,  thesursolid  ;  by  a  sixth,  the  cube  of  the  square,  or  square  of  the  cube. 
When  heterogeneous  colours,  or  dissimilar  unknown  quantities,  are  multiplied  together,  the  result 
is  a  (bhinita)  product  or  factum.  Crishn. 

Bhdvita,  future,  or  to  be.  It  is  a  special  designation  of  a  possible  operation,  indicating  the  raul» 
tiplication  of  unlike  quantities.  Su'r. 

Like  the  rest  of  these  algebraic  terms,  it  is  signified  by  its  initial  syllable  (bh'i)-  Thus  the  pro- 
duct of  two  unknown  quantities  is  denoted  by  three  letters  or  syllables,  a&y&.  cd  bhd,  c6.  n'l  bhd,  &c. 
Or,  if  one  of  the  quantities  be  a  higher  power,  more  syllables  or  letters  are  requisite:  for  the  square, 
cube,  &c.  are  likewise  denoted  by  initial  syllables,  la,  gha,  in-ra,  va-gha  (or gha-ra),  gha-gha,  &iC. 
Thus  yd  la.  cd  gha  bhd  will  signify  the  square  of  the  first  unknown  quantity  multiplied  by  the  cube 
of  the  second. 

A  dot  is,  in  some  copies  of  the  text  and  its  commentaries,  interposed  between  the  factors,  with- 
out any  special  direction,  however,  for  this  notation. 

'  Viz.  square  and  square-root ;  cube  and  cube-root. — Crishn.    Also  reduction  of  fractions,  to 
a  common  denominator,  rule  of  three,  progression,  mensuration  of  plane  figure,  and  the  whole  of . 
what  is  taught  in  simple  arithmetic.  Sua. . 

•  In  §18. 

'  As  well  as  the  other  methods  there  taught. — Crishn.     See  LUdxati,  §  14 — 15. 


14t 


VrJA-GAN'ITA. 


Chapter  I. 


the  result  of  their  multiplication  inverting  the  affirmative  and  negative  signs 
in  the  multiplicand,  or  in  the  nmltiplicator,  or  in  both.* 

Statement :     «a  5    rw  1     _,     . 

yaS    ruZ    Product:  yavlS  yal    ru  2. 

Statement :    vo  5    rw  1     t)    j     .  ,v        ~ 

ya3    ru2,     ^^0^"^*^=  yav  15  yal    ru  2. 

Statement :     ya  5    ru  I     ^     i     ^ 

■^     ■         •      Product:    yav  15    ya7    ru  2. 
ya3   ru2  ^  ^ 

[Statement :     ya5    ru\     ^     ,     ^  , ,        „         •  ,, 

^  ^    ■         •      Product:    yavlS    ya7    rw  2.1* 

ya3    ru2  ^  ^ 

24.  Rule  for  division :  Those  colours  or  unknown  quantities,  and  abso- 
lute numbers,  by  which  the  divisor  being  multiplied,  the  products  in  their 
several  places  subtracted  from  the  dividend  exactly  balance  it,'  are  here  the 
quotients  in  division. 

Example.  Statement  of  the  product  of  the  foregoing  multiplication,  and 
of  its  multiplicator  now  taken  as  divisor :  yav\5  ya7  ru  2.  It  is  divi- 
dend ;  and  the  divisor  \%ya  3    ru  Q. 

Division  being  made,  the  quotient  found  is  the  original  multiplicand  ya  5 

ru  I. 


'  The  concluding  passage  is  read  in  three  different  ways ;  the  one  implying,  that  the  multipli- 
cand, affirmative  and  negative,  is  to  be  inverted,  or  the  multiplicator;  the  second  indicating,  that 
the  terras  of  the  multiplicand  or  multiplicator  with  their  signs  are  to  be  transposed  ;  the  third  sig- 
nifying, that  the  terms  of  the  multiplicand  or  multiplier  must  have  their  signs  changed. — CafsHK. 
The  commentator  prefers  the  reading  and  interpretation  by  which  the  signs  only  are  reversed. 

*  This  fourth  example  is  exhibited  by  Crishn'a-biiatta. 

Multiplication  is  thus  wrought  according  to  the  commentator.  Example  1st, 

ya  5    ru  1  ya  3  i/a  v  \5   ya    3 

ya  5    ru  I  ru  2  ya  10    ru2 


yav\5   ya    7    ru2 


*  Exhaust  it :  leave  no  residue. 


Section  IV. 


LOGISTICS. 


149 


i 


Statement  of  the  second  example:  yav  \5  yal  rw  2  dividend,  thfc 
divisor  being  ya  3  ru  2.  Answer:  The  quotient  found  is  the  original  mul- 
tiplicand ya  5    ru  1. 

Statement  of  the  third  example :    ya  w  15    yal    ru  2,  dividend,  with  di* 

visor  ya  3    ru  2.     The  quotient  comes  out  ya  5    ru  I,  the  original  multi- 
plicand. 

[Statement  of  the  fourth  example  :  yav  15  ya?    ru  Q  dividend,  with  di- 
visor _yrt  3    ru  2.     Answer:  ya  5    ru  I,  the  original  multiplicand.] 

25.  Example  of  involution.'  Tell  me,  friend,  the  square  of  unknown 
four  less  known  six. 

Statement:    _ya  4    ru6.     Answer:     The  square  is  j/flw  16   ^^0  48    ru  36. 

26.  Rule  for  the  extraction  of  the  square-root :  Deducting  from  the 
squares  which  occur  among  the  unknown  quantities  their  square-roots,  sub- 
tract from  the  remainder  double  the  product  of  those  roots  two  and  two ; 
and,  if  there  be  known  quantities,  finding  the  root  of  the  known  number,* 
proceed  with  the  residue  in  the  same  manner.' 

Example.  Statement  of  the  square  before  found,  now  proposed  for  ex- 
traction of  the  root :    yav  15    ya  48    ru  36. 

Answer :     The  root  is  ya  4   ru  6  or  ya  4    ru  6. 


'  The  square  being  the  product  of  the  multiplication  of  two  liite  quantities,  involution  is  com- 
prehended under  the  foregoing  rule  of  multiplication,  §  21 ;  and  therefore  an  example  only  is  here 
given.  Cbi'shn. 

If  the  absolute  number  do  not  yield  a  square-root,  the  proposed  quantity  was   not  an  exact 
square.  Crishn. 

'  When  the  terms  balance  without  residue,  those  roots  together  constitute  the  root  of  the  pro- 
posed square.'  Cbishx. 


Hi  VI'JA-GAN'ITA.  Chapter  I. 

Arithmetical  Oparations  with  several  Unknown  Quantities. 

27.  Example.  "  So  much  as"  three,  "  black"  five,  "  blue"  seven,  all 
affirmative  :  how  many  do  they  make  with  negative  two,  three,  and  one  of 
the  same  respectively,  added  to  or  subtracted  from  them  ? 

Statement :    ya  3    ca  5    ni  7     Answer :    Sum  ya  \    ca  2    ni    6. 
ya  k    ca  3    ni  1  Difference  ya  5    ca  8    ni    8. 

28.  Example.  Negative  "  so  much  as"  three,  negative  "  black"  two, 
affirmative  "  blue"  one,  together  with  unity  absolute  :  when  these  are  mul- 
tiplied by  the  same  terms  doubled,  what  is  the  result?  And  when  the  pro- 
duct of  their  multiplication  is  divided  by  the  multiplicand,  what  will  be  the 
quotient  ?  Next  tell  the  square  of  the  multiplicand,  and  the  root  of  this 
square. 

Statement:  Multiplicand  j/a  3  ca  9,  nil  ru  I.  Multiplier  3/a  6  ca  4 
ni  2    ru  2.     Answer:    The  product  is  ^a  r  18    ca  v  S    niv  9,   ya.  ca  bh  24 

ya.  ni  bh  1 2    ca.  ni  bh  8    ru  2. 

From  this  product  divided  by  the  multiplicand,  the  original  multiplicator 

comes  out  as  quotient  ya6    ca  i   ni  2    ru  ^. 

Statement  of  the  foregoing  multiplicand  for  involution  :  ya  3  cak  ni  1 
ru\.  Answer:  The  square  is  ^ai>  9  ca  o  4  nivX  ya.  ca  bh  12  ya.nibhQ 
ca  ni  bh  4-   ya  6    caAs   ni  2    ru  \. 

From  this  square,  the  square-root  being  extracted,  is  ya3  ca  2  ni  1  ru\ 
[or^fl  3    ca  2    ni  1    ru  1.]* 

'  For  both  these  roots  being  squared  yield  the  same  result.  CRrsHN. 


(     145     ) 


SECTION    V. 


.'^M^u 


SURDS. 

29.  Rule  for  addition,  subtraction,  &c.  of  surds:*  Term  the  sum  of  two 
irrationals  thegreat^  surd;  and  twice  the  square  root  of  their  product,  the  less 
one.  The  sum  and  difference  of  these  reckoned  like  integers  are  so  [of  the 
original  surd  roots].'     Multiply  and  divide  a  square  by  a  square.* 

30.  But  the  root  of  the  quotient  of  the  greater  irrational  number  divided 
by  the  less,*  being  increased  by  one  and  diminished  by  one;  and  the  sum  and 

'  Coram,  a  surd  or  irrational  number.  One,  the  root  of  which  is  required,  but  cannot  be  found 
without  residue. — Crishx.  That,  of  which  when  the  square-root  is  to  be  extracted,  the  root  does 
not  come  out  exact. — Gan.  "  A  quantity,  the  root  of  which  is  to  be  taken,  is  named  Carani." 
Nara'yan'a  cited  by  Sun.  Not-generally  any  number  which  does  not  yield  an  integer  root:  for, 
were  it  so,  every  such  number  (as  2,  3,  5,  6,  Sec.)  must  be  constantly  treated  as  irrational.  It  only 
becomes  a  surd,  when  its  root  is  required;  that  is,  when  the  business  is  with  its  root,  not  with  tho 
number  itself.  Crishn. 

A  surd  is  denoted  by  the  initial  syllable  ca.  It  will  be  here  written  c  to  distinguish  it  from  cd 
the  second  unknown  quantity  in  an  algebraic  expression. 

*  Mahati,  intending  mahati  carani  a  great  surd,  being  the  sum  of  two  original  irrational  num- 
bers-  Laghu,  small,  is  by  contrast  the  designation  of  the  less  quantity  to  be  connected  with  it. 
The  same  terms,  mahati  and  laghvi,  are  used  in  the  following  stanza,  §  30,  with  a  different  sense, 
importing  the  greater  and  less  original  surds.     See  Su'r.  and  Crishn. 

'  The  sum  and  difference  of  the  quantities  so  denominated  are  sura  and  difference  of  the  two 
original  surds.  Su'r.  and  Crishn. 

♦  This  is  a  restriction  of  a  preceding  rule  concerning  multiplication  of  irrational  numbers.  §  22. 
— Cafsnu'.  The  author  in  this  place  hints  the  nature  of  surds,  under  colour  of  giving  a  rule  for 
the  multiplication  and  division  of  them. — Su'r.  If  a  rational  quantity  and  an  irrational  one  are  to 
be  multiplied  together,  the  rational  one  is  previously  to  be  raised  to  the  square  power;  the  irra- 
tional quantity  being  in  fact  a  square.     See  Sua.  and  Crishn. 

'  In  like  manner,  if  the  less  surd  divided  by  the  greater  be  a  fraction  of  which  the  root  may  be 
found,  this,  with  one  added  and  subtracted,  being  squared  and  multiplied  by  the  greater  surd,  will 
give  the  sura  and  difference  of  the  two  surds,  CaisHN. 

V 


146  VI'JA-GAN'ITA.  Chapter  I. 

remainder,  being  squared  and  multiplied  by  the  smaller  irrational  quantity, 
are  respectively  the  sum  and  difference  of  the  two  surd  roots.  If  there  be  no 
rational  square-root  [of  the  product  or  quotient],  they  must  be  merely  stated 
apart. 

81.  Example.  Say,  friend,  the  sum  and  difference  of  two  irrational  num- 
bers eight  and  two:  or  three  and  twenty-seven;  or  seven  and  three;  after 
full  consideration,  if  thou  be  acquainted  with  the  six-fold  rule  of  surds. 

.  Statement:     c2    c  8.     Answer:     Addition  being  made,  the  sum  is  c  18. 
Subtraction  taking  place,  the  difference  is  c  2.' 

Statement:     c3    c  27-     Answer:     Sum  c  48.     Difference  e  12. 

Statement:  c  3  c7-  Answer:  Since  their  product  has  no  root,  they 
are  merely  to  be  stated  apart:     Sum  c  3    c  7-     Difference  c  3    c  7. 

32.  Example.  Multiplicator  consisting  of  the  surds  two,  three,  and 
eight;  multiplicand,  the  surd  three  with  the  rational  number  five:  tell 
quickly  their  product.  Or  let  the  multiplier  be  the  two  surds  three  and 
twelve  less  the  natural  number  five. 

Statement:     Multiplier  c  2    c3    c  8.     Multiplicand  c  3    c  25. 

Here,  to  abridge  the  work,  previously  adding  together  two  or  more  surds- 
in  the  multiplier,  or  in  the  multiplicand,  and  in  the  divisor  or  in  the  dividend, 
proceed  with  the  multiplication  and  division.  That  being  done  in  this  case,, 
the  multiplier  becomes  c  18  c  3.  Multiplicand  as  before  c  25  c  3.  Mul- 
tiplication being  made,  the  product  is  found  c  9    c  450    c  75    c  54. 

33.  Maxim.     The  square  of  a  negative  rational  quantity  will  be  nega- 

•  The  numbers  8  and  2  added  together  make  10,  the  mahati  or  great  surd.  Their  product  !& 
yields  the  root  4;  which  doubled  furnishes  8  for  the  laghu.  The  sum  and  diflerence  of  these  are 
18  and  2.  Or  by  the  second  method,  the  greater  irrational  8  divided  by  the  less  2,  gives  4  ;  the 
root  of  which  is  2.  This  augmented  and  diminished  by  1,  affords  the  numbers  3  and  1  ;  whose 
squares  are  9  and  1.  These,  being  multiplied  by  the  smaller  irrational  number,  make  18  and  2,  a» 
Itefore. 


Section  V.  LOGISTICS.  147 

tive,  when  it  is  employed  on  account  of  a  surd;  and  so  will  the  root  of  a 
negative  surd  be  negative,  Avhen  it  is  formed  on  account  of  a  rational  num- 
ber.' 

Statement  of  the  second  example:  MultipUcator  c  25  c3  c  12.  Mul- 
tiplicand c  25  c  3.  Adding  together  two  surds  in  the  multiplier,  it  be- 
comes c  25  c  27.  The  product  of  the  multiplication  is  c  625  c  675  c  75 
c  81.  Among  these  the  roots  of  c  625  and  c  81,  namely  25  and  9,  being 
added  together,  make  the  natural  number  16:  and  the  sum,  consisting  in  the 
difference,  of  c  675  and  c  75,  is  c  300.  The  product  therefore  is  rw  16 
cSOO. 

Statement  of  the  foregoing  product  for  dividend  and  the  multiplier  for 
divisor:     Dividend  c  9    c  450    c  73    c  54.     Divisor  c  2    c  3    c  8. 

Adding  together  two  surds,  the  divisor  becomes  c  18  c  3.  Then  proceed- 
ing as  directed  (§  24),  the  quotient  is  the  original  multiplicand  ru  5    c  3. 

Statement  of  the  second  example:  Dividend  c  256  c  300.  Divisor  c  25 
c  3    c  12. 

Adding  together  two  surds,  the  divisor  becomes  c  25  c  27.  Here  also, 
proceeding  as  before,  the  quotient  found  is  the  original  multiplicand  ru  5    c  3. 

34 — 35.  Or  the  method  of  division  is  otherwise  taught:  Reverse  the 
sign,  affirmative  or  negative,  of  any  surd  chosen  in  the  divisor;  and  by  such 
altered  divisor*  multiply  the  dividend  and  original  divisor,  repeating  the  ope- 
ration [if  necessary]  so  as  but  one  surd  remain  in  the  divisor.  The  surds, 
which  constituted  the  dividend,  arc  to  be  divided  by  that  single  remaining 
surd;  and  if  the  surds  obtained  as  a  quotient  be  such  as  arise  from  addition, 

'  This  is  a  seeming  exception  to  the  maxim,  that  a  negative  quantity  has  no  square-root  (§  10). 
But  the  sign  belongs  to  the  surd  root  not  to  the  entire  irrational  quantity.  When  therefore  a  nega- 
tive rational  quantity  is  squared  to  bring  it  to  the  same  form  with  a  surd,  with  which  it  is  to  be 
combined,  it  retains  the  negative  sign  appertaining  to  the  root :  and  in  liice  manner,  when  a  root  is 
extracted  out  of  a  negative  rational  part  of  a  compound  surd,  the  root  has  the  negative  sign.     Sx/r, 

*  Or  by  any  number  which  may  serve  for  extirpating  some  of  the  terms.  Since  the  dividend 
and  divisor  being  multiplied  by  the  same  quantity,  the  quotient  is  unchanged  :  and  the  object  of 
the  rule  is  to  reduce  the  number  of  terms  by  introducing  equal  ones  with  contrary  signs.    See  Sub. 

U  2 


148  VI'J  A-GAN'ITA.  Chapter  I. 

they  must  be  separated  by  the  following  rule  for  the  resolution  of  them,'  iu 
such  form  as  the  questioner  may  desire.'* 

S6.  Rule:  Take  component  parts  at  pleasure  of  the  root  of  a  square,  by 
which  the  compound  surd  is  exactly  divisible:  the  squares  of  those  parts, 
being  multiplied  by  the  former  quotient,*  are  severally  the  component  surds.* 

Statement:     Dividend  c  9    c  450    c  75    c  54.     Divisor  c  18    c  3. 

Here  allotting  the  negative  sign  to  the  surd  three  in  the  divisor,  it  he- 
come  c  18  c  3.  Multiplying  by  this  the  dividend,  and  adding  the  surtb 
together,'  the  dividend  is  c  5625  c  675.  In  like  manner,  the  divisor  be- 
comes c  225.     The  dividend  being  divided  by  this,  the  quotient  is  c  25    c  3. 

Example  2d.     Dividend  c  300    c  25*6.     Divisor  c  25    c  27. 

Here  assigning  to  the  surd  twenty-five  the  affirmative  sign,  multiplying 
the  dividend,  and  taking  the  difference  of  affirmutive  and  negative  surds,  the 
dividend  is  c  100  c  12;  and  the  divisor  c  4.  Dividing  the  dividend  by 
this,  the  quotient  is  c  25    c  3. 

*  VUlhha-sutra,  a  rule  for  an  operation  converse  of  that  of  addition :  (§  Sff ;  which  comparft 
with  §  30.) 

*  They  must  be  resolved  into  such  portions  as  the  nature  of  the  question  may  require. 

'  By  former  quotient,  that  which  is  previously  found  under  this  rule  is  meant :  the  quotient  of 
the  surd  by  a  square  which  measures  it.     See  Sur. 

*  This  rule,  reversing  the  operations  directed  by  §  30,  is  the  converse  of  that  rule. — See  So'«. 
However,  to  make  the  contrast  exact,  the  root  of  the  square  divisor  of  the  surd  should  be  resolved 
into  parts  one  of  which  should  be  unity. 

'  The  dividend,  multiplied  by  the  altered  divisor  which  comprises  two  terms,  gives  the  product 
c  162    C8100    c  1350    C972 
e  162    c  27        c  1350    c  225 

Expunging  like  quantities  with  contrary  signs,  the  product  is  c  8100  c  972  c  225  c  27  ;  and 
adding  together  the  first  and  third  terms,  and  second  and  fourth,  (that  is,  taking  their  differences  i>y 
§  29 — 30)  the  product  is  reduced  to  two  terms  c  5625    c  675. 

Again  the  original  divisor,  multiplied  by  the  altered  one,  gives  c  324    c  54      Expunging  equal 

c      9    c  54 
quantities  with  contrary  signs,  the  product  is  c  324   c  9 }  reducible  by  addition  (that  is,  by  finding 
the  difference,  §  30)  to  c  225. 

The  reduced  dividend  c  5625  c  675,  divided  by  this  divisor  c  225,  gives  the  quotient  c  25    c  3. 

In  like  manner,  by  this  process  in  the  last  example,  the  dividend  becomes  c  8712  c  1452  ;  and 
the  divisor  c  1 84.     Whence  the  quotient  c  1 8    c  3  ;  resolvable  by  §  36  into  c  2    c  8    c  3.     SuR. 


Section  V.  LOGISTICS.  149 

Next  in  the  former  example,  making  the  multiplicand  a  divisor,  the  state- 
ment is  dividend  c9    c  450    c  75    c  54.     Divisor  c  25    c  3. 

Here  also,  assigning  to  the  surd  three  the  negative  sign,  multiplying  the 
dividend,  and  adding  surds  together,  the  dividend  becomes  c  8712  c  1452  ; 
and  the  divisor  c  484.  The  dividend  being  divided  by  this,  the  quotient  is 
the  multiplier  c  18  c  3.  The  original  multiplicator  comprised  three  terms. 
The  compound  surd  c  18  (under  the  rule  for  the  resolution  of  such:  §  36) 
being  divided  therefore  by  the  square  nine,  gives  the  quotient  2  without  re- 
mainder. The  square  root  of  nine  is  3.  Its  parts  1  and  2.  Their  squares 
1  and  4.  These,  multiplied  by  the  quotient  2,  make  2  and  8.  Thus  the 
origiual  multiplicator  is  again  found  c  2    c8    c  3. 

37 — 38.  Examples  of  involution.  Tell  me,  promptly,  learned  friend,  the 
square  of  the  three  surds  two,  three,  and  four;  that  of  two  surds  numbering 
two  and  three;  and  separately  that  of  the  united  irrationals  six,  five,  two,  and 
three;  as  well  as  of  eighteen,  eight,  and  two:  and  the  square  roots  of  the 
squared  numbers. 

Statement  1st.  c2  c3  c  5.  And  2d.  c3  c  2.  Also  3d.  c6  c5  cS 
c  3.     Likewise  4th.  c  18    cS    c  2. 

Proceeding  by  the  rule  of  involution^  {Lildvat'i,  \  18 — 19)  the  squares  are 
found,  1st.  rw  10  c  24  c  40  c  60.  2d.  ru  5  c  M.  3d.  ru  16  c  120 
c  72  c  60  c  48  c  40  c  24.  Here  also,  to  abridge  the  work,  surds  are  to 
be  added  together  when  practicable,  whether  in  squaring,  or  in  extraction  of 
the  square  root.  Thus  4th.  c  18  c2  c  8.  The  sum  of  these  is  c  72.  Its. 
square  is  i-u  72. 

39 — 40.  Rule  for  finding  the  square  root:  From  the  square  of  the 
rational  numbers  contained  in  the  proposed  square,  subtract  integer  num- 
bers* equal  to  one,  two,  or  more  of  its  surds;  the  square  root  of  the  re- 

iinni  In'. 

'  With  this  difference  however,  that  instead  of  twice  the  multiple  of  rational  quantities,  four 
times  the  multiple  of  irrational  numbers  is  to  be  taken  :  under  the  »ule,  that  a  square  is  to  be  mul- 
tiplied by  a  square  (5  29).  iSll\i  <!•>  SuR. 

*  A  rational  number  equal  to  the  numbers  that  express  the  irrational  terms  is  subtracted  :  and 
the  author  therefore  says  "  subtract  integer  numbers  frupaj  equal  to  one  or  more  surds,"  to  indi- 
cate, that  subtraction  as  of  surds  (^  29)  is  not  here  intended.  Si/r. 


150  V  r  J  A  -  G  A  N'l  T  A.  C  h  after  I. 

mainder  is  to  be  severally  added  to,  and  subtracted  from,  the  rational  num- 
ber: the  moieties  of  this  sum  and  difference  will  be  two  surds  in  the  root. 
The  largest  of  them  is  to  be  used  as  a  rational  number,  if  there  be  any  surds 
in  the  square  remaining;  and  the  operation  repeated  [until  the  proposed 
quantity  be  exhausted].* 

Example.  Statement  of  the  second  square,  for  the  extraction  of  its  root : 
ru  5    c  24. 

Subtracting  from  9.5,  which  is  the  square  of  the  rational  number  (5)  a 
number  equal  to  that  of  the  surd  24,  the  remainder  is  1.  Its  square-root  1, 
added  to,  and  subtracted  from,  tlie  natural  number  5,  makes  6  and  4.  The 
moieties  of  which  are  3  and  2,  and  the  surds  composing  the  root  are  found, 

c3  c2.  !'     n  'm/jl    .ae— ^f. 

t  adl  111. 
Statement  of  the  first  square :     rw  10   c  24    c40    c  60.  >/j 

From  the  square  of  the  rational  number  (10)  viz.  100,  subtract  numbers 
equal  to  two  of  the  surds  twenty-four  and  forty ;  the  remainder  is  36 ;  and 
its  square-root  6,  subtracted  from  the  natural  number  10,  and  added  to  it, 
makes  4  and  16;  the  moieties  of  which  are  2  and  8.  .The  first  is  a  surd  in 
the  root,  c  2.  Putting  the  second  for  a  rational  number,  the  same  operation 
is  again  to  be  performed  with  the  rest  of  the  surds.  From  the  square  of  this 
then  treated  as  a  rational  number,  64,  subtracting  the  number  sixty,  the  re- 
mainder is  4 ;  and  its  root  2  ;  which,  subtracted  from  that  rational  number, 
and  added  to  it,  severally  makes  6  and  10 ;  the  moieties  whereof  are  3  and  S. 
They  are  surds  in  the  root:  c  3  c  5.  Statement  of  the  whole  of  the  surds 
composing  the  root,  in  their  order  as  found  ;  c  2    c  3    c  5. 

Statement  of  the  third  square  :  ru  16    c  120    c  72    c60    c48    c40    c24. 

•  From  the  involution  of  surds  as  above  shown,  it  is  evident,  that  the  rational  number  is  the  sum 
-■at 
of  the  numbers  of  the  original  surds:  and  the  irrationals  in  the  square  are  four  times  tiie  product 

of  the  original  terms,  two  and  two.  If  they  be  subtracted  from  the  square  of  the  sum  of  tlie  num- 
bers, the  remainder  will  be  the  square  of  the  difference.  Its  square-root  is  the  difference  itself. 
From  the  sum  and  difference,  the  numbers  are  found  by  the  rule  of  concurrence  {IMvati,  §  55). 
The  least  [or  sometimes  the  greatest]  of  the  numbers  thus  found  is  one  of  the  original  terms  ;  and 
the  greater  [or  sometimes  the  less]  number  is  the  sum  of  the  remaining  irrational  terms  :  it  is  used, 
therefore,  as  the  rational  number,  in  repeating  the  operation;  and  so  on,  until  all  the  terms  of  the 
root, are  extracted.  .  .    ;i  li..  Su'r. 


Section  V.  ./LOGISTICS.  151 

From  the  square  of  the  rational  number  (16)  0,56,  subtracting  numbers 
equal  to  three  surds,  a  hundred  and  twenty,  seventy-two  and  forty-eight, 
making  240,  and  proceeding  as  before,  two  portions  are  found,  6  and  10. 
Again,  from  the  square  of  the  latter  as  a  rational  number,  100,  subtract 
numbers  equal  to  two  surds  twenty-four  and  forty,  making  64,  and  proceed 
as  before ;  two  portions  are  found  2  and  8.  Again,  from  the  square  of  the 
latter  as  a  rational  number  64,  subtract  a  number  equal  to  the  surd  sixty ; 
two  more  portions  are  found  3  and  5.  Hence  statement  of  the  surds  com- 
posing the  root,  in  order  as  found,   c6   c  Z    c  3    c  5. 

Statement  of  the  fourth  square  :  ru  72    c  0. 

Its  square-root  c  72.  This  surd-root  originally  consisted  of  three  terms. 
Proceeding  then  to  the  resolution  of  it  by  the  rule  (§  36),  79i  divided  by  36 
gives  the  quotient  2.  The  square-root  of  thirty-six,  6,  comprises  three  por- 
tions 3,  2,  1.  Their  squares  are  9,  4  and  1 ;  which  multiplied  by  the  former 
quotient  (2)  make  18,  8  and  2.  The  resolution  of  the  surd  then  exhibits 
C  18  c8  c  2. 

i,  41.  Rule:  If  there  be  a  negative  surd-root  in  the  square,  treating  that 
irrational  quantity  as  an  affirmative  one,  let  the  two  surds  in  the  root  be 
found  [as  before] ;  and  one  of  them,  as  selected  by  the  intelligent  calculator, 
must  be  deemed  negative.* 

42.  Example.  Tell  me  the  square  of  the  difference  of  the  two  surds 
three  and  seven;  and  from  the  square  tell  the  root. 

Statement :     c  3    c7    or  c  3    c  7. 

The  square  of  either  of  these  quantities  is  the  same;  ru  10    c  84. 

Here  treating  the  negative  surd-root  in  the  square  as  an  affirmative  irrational 
quantity,  find  the  two  surds  by  proceeding  as  before;  and  let  either  of  them 
at  pleasure  be  made  negative.     Thus  the  root  is  found  c  3    c  7 ;  or  c  3    c  7. 

43.  Example.  Let  the  irrational  numbers  two,  three  and  five  be  seve- 
rally affirmative,  affirmative  and  negative ;  or  let  the  positive  and  negative 

The  rule  is  grounded  on  the  maxim,  that  the  square  of  a  negative  quantity  is  affirmative; 
and  that  there  is  no  square-root  of  a  negative  quantity.  §  10.  Su'». 


tif 


VI'JA-GAN'ITA. 


Chapter  I. 


signs  be  reversed.     Tell  their  square;  and  from  the  square  find  the  root;  if 
thou  know,  friend,  the  sixfold  method  of  surds. 

Statement :  c2  c  3  c5;  or  c2  c  3  c  5.  Their  square  is  the  same 
ru  10    c  24    c40    c60. 

Here  affirmative  rationals  equal  to  the  negative  irrationals  being  sub- 
tracted from  the  square  of  the  rational  number  (10),  100,  the  remainder  is  0. 
The  rational  number  with  the  root  added  and  subtracted,  being  halved,  the 
surds  are  c 5  c5.  One  is  made  negative  c5;  and  the  other  treated  as  a 
rational  number.  Statement :  r?<  5  c  24.  Proceeding  as  before,  the  surds 
are  found,  both  affirmative,  c  3    c  2. 

Next  subtracting  affirmative  rationals  equal  to  the  two  surds  c  24  c  60, 
viz.  84,  from  the  square  of  the  rational  number,  and  proceeding  as  before, 
the  surds  found  are  c  3  c7.  The  largest  of  these  is  made  negative ;  and, 
with  its  number  taken  as  rational,  proceeding  as  before,  the  other  surds  come 
out  c5    c  Q.     The  greatest  of  these  again  is  taken  as  negative,  c  5. 

Then,  with  the  second  example,  and  in  the  first  instance,  the  two  surds 
being  c5  c5,  one  is  taken  as  negative;  and,  its  number  being  used  as  a  ra- 
tional one,  the  two  portions  of  surds  deduced  from  the  negative  one,  are  both 
negative  c  3  c  2.  In  the  second  case,  proceeding  as  directed,  the  surds  of 
the  root  come  out,  c  2    c  3    c  5. 

It  might  be  so  understood  by  an  intelligent  mathematician,  though  it 
were  not  specially  mentioned.  This  matter  likewise  has  not  been  explained 
at  length  by  former  writers.  It  is  by  me  set  forth,  for  the  instruction  of 
youth. 

44 — 47.  Rule  :  The  number  of  irrational  terms  in  the  square  quantity 
answers  to  the  sum  of  the  progression  of  the  natural  numbers  one,  &c.'  In 
a  square  comprising  three  such  terms,  integer  numbers  equal  to  two  of  the 
terms  arc  to  be  subtracted  from  the  square  of  the  rational  number,  and  the 


'  The  sums  of  the  progression  are  for  the  1st  term  1  ;  for  the  2(1,  3 ;  for  the  3cl,  6  ;  for  the  Ith, 
10;  for  the  5th,  15, — Sur.  The  rational  portion  of  the  square  comprises  as  many  terms  as  there 
were  surds  in  the  root ;  and  the  number  of  irrational  terms  in  the  square  answers  to  the  sum  of 
the  progression  continued  to  one  less  than  the  number  of  radical  terms :  as  the  author's  subsequent 
comment  shows. 


Section  V.  LOGISTICS.  I5S 

square  root  [of  the  remainder]  to  be  then  taken;  in  one  comprising  six  such, 
integers  equal  to  three  of  them;  in  one  containing  ten,  integers  equal  t© 
four  of  them ;  in  one  comprehending  fifteen,  integers  equal  to  five.  If  in 
any  case  it  be  otherwise,  there  is  error.*  Those  terms  are  to  be  subtracted 
from  the  square  of  the  rational  number,  which  are  exactly  measured''  by 
four  times  the  smaller  radical  surd  thence  to  be  deduced.  The  quotients 
found  by  that  common  measure  are  surds  in  the  root;  but,  if  they  be  not  so, 
as  not  answering  by  the  rule  of  remainder  (§  39)'  that  is  not  the  root.* 

In  a  square  raised  from  irrational  terms,  there  must  necessarily  be  rational 
numbers.  The  square  of  a  single  surd  consists  of  a  rational  number  only. 
That  of  two  contains  one  surd  with  a  rational  number;  that  of  three  com- 
prises three;  that  of  four  comprehends  six;  that  of  five,  ten ;  and  that  of  six, 
fifteen.  Hence,  in  the  square  of  two,  &c.  terms,  the  number  of  surd  terms, 
besides  the  rational  numbers,  answer  severally  to  the  sums  of  the  arithmetical 
progressions  [of  natural  numbers]  one,  &c.  But,  if  there  be  not  so  many  in 
the  example,  compound  surds  are  to  be  resolved  (§  36)  to  complete  tiie  num- 
ber of  terms;  and  the  root  is  then  to  be  extracted.     That  is  the  meaning. 

In  a  square  comprising  three  such  terms,  [integer  numbers  equal  to  two, 
&c.]    The  sense  of  the  whole  passage  is  clear. 

48.  Example.  Say,  learned  man,  what  is  the  root  of  a  square  consisting 
of  the  surds  thirty-two,  twenty-four,  and  eight,  with  the  rational  number 
ten? 

Statement:     rw  10    c  32     c24    c8. 

Here,  as  the  square  comprises  three  irrational  terms,  first  subtract  integer 
numbers  equal  to  two  of  them  from  the  square  of  the  rational  number,  and 

'  If  in  any  supposable  case  an  answer  come  out,  it  is  not  taken  as  the  true  root.  It  is  wrong; 
and  the  question  was  ill  proposed.  Sub. 

*  Apaxartana,  division  without  remainder  by  a  common  measure.     §  54. 

'  By  the  rule  for  adding  and  subtracting  the  root  of  the  remainder,  &c.     §  SQ.  Sua. 

♦  As  many  of  the  irrational  terms  in  the  square,  as  are  multiples  of  one  of  the  radical  irrationals, 
being  subtracted  in  the  first  instance,  they  must  be  divisible  without  remainder  by  four  times  that 
radical  term ;  and  the  quotients  will  be  the  rest  of  the  radical  terms  :  as  is  apparent  from  what  has 
been  said  concerning  the  involution  of  a  quantity  consisting  of  surd  terms.  (See  under  §  37.)  If 
then  those  quotients  do  not  answer,  as  not  agreeing  with  the  terms  found  by  the  preceding  (§  39 — 
40),  the  root  is  wrong.  Su'r. 


154  VIJ'A-GAN'ITA.  Chapter  I. 

extract  the  root  of  the  remainder;  and  afterwards  work  with  one  term. 
Proceeding  in  that  manner,  there  is  here  no  root.  Hence  it  appears,  that 
tlic  [proposed  quantity]  has  not  an  exact  root  consisting  of  surd  terms.  But, 
Avere  it  not  for  the  restriction,  a  number  equal  to  the  whole  of  the  surds 
might  be  subtracted,  and  a  supposed  root  be  thus  found:  namely,  c  8  c2. 
This,  however,  turns  out  wrong;  for  its  square  is  ru  18.*  Or  summing  two 
of  the  terms,  thirty-two  and  eight,  [by  §30]  the  expression  becomes  ru  10 
c  72    c  24.     Whence  the  root  is  found  rw  2    c6.     But  this  also  is  wrong.'^ 

49.  Example.  Say  what  will  be  the  root  of  a  square  which  contains 
surds  equal  to  fifteen,  eleven,  and  three,  all  multiplied  by  four;  with  the 
rational  number  ten? 

Statement:     ru  10     c  60     c52     c  12. 

In  this  square  three  irrational  terms  occur.  Taking  then  two  of  them,-' 
fifty-two  and  twelve,  and  subtracting  an  integer  equal  to  their  amount  from 
the  square  of  the  rational  number,  two  surds  of  the  root  come  out  c  8  c  2. 
But  four  times  the  least  of  them,  8,  docs  not  measure  the  two  terms  fifty-two 
and  twelve.  These  then  are  not  to  be  subtracted :  for  the  tenor  of  the  rule 
(§  46)  is  "  Those  temis  are  to  be  subtracted,  which  are  measured  by  four 
times  the  smaller  radical  thence  to  be  deduced."  Here  the  rule  is  not  ri- 
gidly restrictive  to  the  least  surd ;  but  sometimes  applies  to  the  greater. 

Putting:  the  radical  surd  as  a  rational  number,  the  other  two  irrational  terms 


*e> 


come  out  c5    c  3.     This  too  is  wrong,  for  the  square  of  c  5    c  3    c  2,  is  rw  10 
c24    c40    c60.' 

50.  Example.  Say  what  will  be  the  root  of  a  square  which  consists  of 
three  surds  eight,  fifty-six,  and  sixty;  with  the  rational  number  ten? 

Statement:     rw  10     c8     c  56    c60. 

Subtracting  the  two  first  terms  eight  and  fifty-six,  and  measuring  those 
terms  by  four  times  the  least  surd  thence  deduced,  8,  two  terms  are  found 
1  and  7.  But  these  do  not  come  out  as  surds  of  the  root  by  the  regular  pro- 
cess of  the  rule  of  remainder  (§  39).  Therefore  those  terms  c  8  c56,  are 
not  to  be  subtracted.     Else  the  root  is  wrong. 

*  For  the  surds  c  8    c  2,  being  added  together  (§  31)  make  c  18.     Its  square  is  of  course  ru  1 8. 

*  For  its  square  is  ru  10  c  96. 

*  Differing  from  the  proposed  square. 


Section  V. 


LOGISTICS. 


155 


5 1 .  Example.  Tell  the  root  of  the  square,  in  which  are  surds  twelve, 
fifteen,  five,  eleven,  eight,  six,  all  multiplied  by  four;  together  with  the  ra- 
tional number  thirteen;  if  thou  have  pretensions  to  skill  in  algebra. 

Statement:     rwlS     c  48     c60    c20     c44.     c  32     c  24. 

Here,  the  square  comprising  six  surd  terais,  integers  equal  to  three  of  them 
are  to  be  first  subtracted  from  the  square  of  the  rational  term,  and  the  root 
of  the  remainder  taken;  then  integers  equal  to  two;  and  afterwards  an  inte- 
ger equal  to  one.  Proceeding  in  this  manner,  no  root  is  found.  Proceeding 
then  differently,  and  first  subtracting  from  the  square  of  the  rational  number, 
an  integer  equal  to  the  first  surd  term;  then  integers  equal  to  the  second  and 
third;  and  lastly  equal  to  the  rest;  the  root  comes  out  c\  c2  c5  c5. 
This,  however,  is  wrong;  for  its  square  is  rw  13    c  8    c  80    c  160. 

Defect  then  is  imputable  to  those  authors,  who  have  not  given  a  limitation 
to  this  method  of  finding  a  root. 

In  the  case  oi  such  irrational  squares,  the  operation  must  be  conducted  by 
taking  the  approximate  roots  of  the  surd  terms,  and  adding  them  to  the  ra- 
tional terms:  whence  the  square  root  is  to  be  deduced.' 

Largest  is  not  rigidly  intended  (§  40).  Sometimes,  therefore,  the  least  is 
to  be  used. 

52.  Example.  Say  what  is  the  root  of  a  square,  in  which  are  the  surds 
forty,  eighty,  and  two  hundred,  with  the  rational  number  seventeen.^ 

Statement:     rw  17     c40     c  80     c200. 

Subtracting  the  two  last  terms  from  the  square  of  the  rational  number,  the 
two  portions  found  are  c  10  cT.  Again  treating  the  smaller  surd  as  a  ra- 
tional number,  the  result  is  c5   c2.     Thus  the  root  is  c  10    c  S    c  2. 


'  A  rule  of  appruximation  for  the  square-root  is  given  in  the  Chapter  on  Algebra,  in  the 
Sidd'hdnta-sundara  of  Jnta'na-ra'ja,  cited  by  his  son  Su'ryada'sa;  "The  root  of  a  near  square, 
with  the  quotient  of  the  proposed  square  divided  by  that  approximate  root,  being  halved,  the  moi- 
ety is  a  [more  nearly]  approximated  root;  and,  repeating  the  operation  as  often  as  necessary,  the 
nearly  exact  root  is  found."  Example  5.  This,  divided  by  two  which  is  first  put  for  the  root,  gives 
f  for  the  quotient:  which  added  to  the  assumed  root  2,  makes  §;  and  this,  divided  by  2,  yielJs  ^ 
for  the  approximate  root. — Su'r.  [Repeating  the  operation,  the  root,  more  nearly  approximated, 
is  W-] 


CHAPTER    II. 


PULVERIZER.' 

53 — 64.  'Rule:  In  the  first  place,  as  preparatory  to  the  investigation  of 
the  pulverizer,  the  dividend,  divisor,  and  atlditive  quantity  are,  if  practicable, 
to  be  reduced  by  some  number.'  If  the  number,  by  which  the  dividend  and 
divisor  are  both  measured,  do  not  also  measure  the  additive  quantity,  the 
question  is  an  ill  put  [or  impossible]  one.* 

54 — 55 — 56.  The  last  remainder,  when  the  dividend  and  divisor  are  mu- 
tually divided,  is  their  common  measure.*     Being  divided  by  that  common 

*  This  is  nearly  word  for  word  the  same  with  a  chapter  in  the  Lildtati  on  the  same  subject. 
(Li7.  Ch.  12.)     See  there,  explanations  of  the  terras. 

The  method  here  taught  is  applicable  chiefly  to  the  solution  of  indeterminate  problems  that  pro- 
duce equations  involving  more  than  one  unknown  quantity.     See  ch.  6. 

*  Ten  stanzas  and  two  halves. 

*  If  the  dividend  and  divisor  admit  a  common  measure,  they  must  be  first  reduced  by  it  to  their 
least  terras;  else  unity  will  not  be  the  residue  of  reciprocal  division;  but  the  common  measure 
will;  (or,  going  a  step  further,  nought.) — Ga'n.  on  Lil.     Crishn.  on  Vy. 

*  If  the  dividend  and  divisor  have  a  common  measure,  the  additive  also  must  admit  it;  and  the 
three  terms  be  correspondently  reduced:  for  the  additive,  nnkss  it  be  [nought  or  else]  a  multiple 
of  the  divisor,  must,  if  negative,  equal  the  residue  of  a  division  of  the  dividend  taken  into  the  mul- 
tiplier by  the  divisor;  and,  if  affirmative,  must  equal  the  complement  of  that  residue  to  the  divisor. 
Now,  if  dividend  and  divisor  be  reducible  to  less  terras,  the  residue  of  division  of  the  reduced  terms, 
multiplied  by  the  common  measure,  is  equal  to  the  residue  of  division  of  the  unreduced  terms. 
Therefore  the  additive,  whether  equal  to  the  residue,  or  to  its  complement,  must  be  divisible  by  the 
common  measure.  Crishn. 

*  The  common  measure  may  equal,  but  cannot  exceed,  the  least  of  the  two  numbers :  for  it 
must  divide  it.  If  it  be  less,  the  greater  may  be  considered  as  consisting  of  two  terras,  one  the 
quotient  taken  into  the  divisor,  the  other  the  residue.  The  common  measure  cannot  exceed  that 
residue;  for,  as  it  measures  the  divisor,  it  must  of  course  measure  the  multiple  of  the  divisor,  and 


PULVERIZER.  157 

measure,  they  are  termed  reduced  quantities.  Divide  mutually  the  reduced 
dividend  and  divisor,  until  unity  be  the  remainder  in  the  dividend.  Place 
the  quotients  one  under  the  other;  and  the  additive  quantity  beneath  them, 
and  cipher  at  the  bottom.  By  the  penult  multiply  the  number  next  above 
it,  and  add  the  lowest  term.  Then  reject  the  last  and  repeat  the  operation 
until  a  pair  of  numbers  be  left.  The  uppermost  of  these  being  abraded  by 
the  reduced  dividend,  the  remainder  is  the  quotient.  The  other  [or  lower- 
most] being  in  like  manner  abraded  by  the  reduced  divisor,  the  remainder  is 
the  multiplier.' 

could  not  measure  the  remaining  portion  or  residue,  if  it  were  greater  than  it.  When  therefore  the 
greater  number,  divided  by  the  lesi,  yields  a  residue,  the  greatest  common  measure,  in  such  case, 
is  equal  to  ihe  remainder,  provided  this  be  a  measure  of  the  less.  If  again  the  less  number,  divided 
by  the  remainder,  yield  a  residue,  the  common  measure  cannot  exceed  this  residue ;  for  the  same 
reason.  Therefore  no  number,  though  less  than  the  first  remainder,  can  be  a  common  measure,  if 
it  exceed  the  second  remainder:  and  the  greatest  common  measure  is  equal  to  the  second  remain- 
der, provided  it  measure  the  first;  for  then  of  course  it  measures  the  multiple  of  it,  which  is  the 
other  portion  of  the  second  number.  So,  if  there  be  a  third  remainder,  the  greatest  common  mea- 
sure is  either  equal  to  it,  if  it  measure  the  second  ;  or  is  less.  Hence  the  rule,  to  divide  the  greater 
number  by  the  less,  and  the  less  by  the  remainder,  and  each  residue  by  the  remainder  following, 
until  a  residue  be  found,  which  exactly  measures  the  preceding  one;  such  last  remainder  is  the 
common  measure.     (§  54).  CRfsHN. 

'  The  substance  of  Cri'shn'a's  demonstration  is  as  follows:  When  the  dividend,  taken  into  the 
multiplier,  is  exactly  measured  by  the  divisor,  the  additive  must  either  be  null  or  a  multiple  of  the 
divisor.  (See  §  63).  If  the  dividend  be  such,  that,  being  multiplied  by  the  multiplicator  and  di- 
vided by  the  divisor,  it  yields  a  residue,  the  additive,  if  negative,  must  be  equal  to  that  remainder; 
(and  then  the  subtractive  quantity  balances  the  residue;)  or,  if  affirmative,  it  must  be  equal  to  the 
difference  between  the  divisor  and  residue ;  (and  so  the  addition  of  that  quantity  completes  the 
amount  of  the  divisor;)  or  else  it  must  be  equal  to  the  residue,  or  its  complement,  with  the  divisor 
or  a  multiple  of  the  divisor  added.  Let  the  dividend  be  considered  as  composed  of  two  portions 
or  terms:  1st,  a  multiple  of  the  divisor;  2d,  the  overplus  or  residue.  The  first  multiplied  by  the 
multiplier  (whatever  this  be),  is  of  course  measured  by  the  divisor.  As  to  the  second,  or  overplus 
and  remainder,  the  additive  being  negative,  both  disappear  when  the  multiplier  is  quotient  of  the 
additive  divided  by  the  remainder,  (the  additive  being  a  multiplier  of  the  residue.)  But,  if  the 
additive  be  not  a  multiple  of  the  remainder,  should  unity  be  the  residue  at  the  first  step  of  the  re- 
ciprocal division,  the  multiplier  will  be  equal  to  the  additive,  if  this  be  negative,  or  to  its  comple- 
ment to  the  divisor,  if  it  be  positive;  and  the  corresponding  quotient  will  be  equal  to  the  quotient 
of  the  dividend  by  the  divisor  multiplied  by  the  multiplicator,  if  the  additive  be  negative;  or  be 
equal  to  the  same  with  addition  of  unity,  if  it  be  affirmative:  and,  generally,  when  reciprocal  divi- 
sion has  reached  its  last  step  exhibiting  a  remainder  of  one,  the  multiplier,  answering  to  the  pre- 
ceding residue,  become  the  divisor,  as  serving  for  that  next  before  it  become  dividend,  is  equal  to 


fi4  VIJ'A-GAN'ITA.  Chapter  II. 

57-  Thus  precisely  is  the  operation  when  the  quotients  are  an  even  num- 
ber.    But,  if  they  be  odd,  the  numbers  as  found  must  be  subtracted  from 

tbe  additive,  if  this  be  negative,  or  to  its  complement,  if  it  be  positive;  and  the  corresponding  quo* 

taent  is  equal  to  the  quotient  of  the  dividend  by  the  divisor  multiplied  by  this  raultiplicator;  but 

with  unity  superadded,  if  the  additive  were  affirmative.     From  this,  the  raultiplicator  and  quotient 

answering  for  the  original  dividend  and  divisor  are  found  by  retracing  the  steps  in  the  method  of 

inversion.    Take  the  following  example : 

Given  Dividend  1211      «  u-.-      n,  7  or,  reduced  to  least  terms,  f  Dividend  173      »  u-.-      a 
r,    •  .n-r    Additive  21  >     '       c  t"    .  i  t^  S  r>;  :  n.     Additive  3. 

Divisor       497  3  §  53  and  54,  (^  Divisor       /I 

The  reciprocal  division  (§  55)  exhibits  the  following  results: 

Dividends.  Divisors.  Quotients.  Residues. 

173                             71                             2  31 

71                            31                            2  9 

31                              9                           3  4 

9                             4                            2  1 

Consider  last  dividend  (9)  as  composed  of  two  terms ;  a  multiple  of  divisor  (4)  and  the  residue; 

(in  the  instance  8  and  1).    Then  the  multiplier  is  equal  to  (3)  the  additive  (this  being  negative); 

and  quotient  is  equal  to  the  multiplier  (3)  taken  into  the  quotient  of  the  simple  dividend  (9)  by  the 

divisor  (4)  :  (in  the  instance  6).     Thus,  observing  the  directions  of  the  rule(§  53,  56)  the  last  term 

in  the  series  is  the  multiplier  for  the  last  dividend,  and  its  product  into  the  term  next  above  it  is 

the  quotient  of  the  last  divisor;  and  the  series  now  is    2    deduced  from  the  series (§  55)  2 

2 
3 

6    Quotient. 
3     Multiplier. 

Hence  to  find  the  multiplier  for  the  next  superior  dividend  and  divisor  (31  and  9)  consider  the 
dividend  as  comprising  two  portions  or  terms;  viz.  27  and  4.  Any  multiple  of  the  first  being  divi- 
sible by  the  divisor  (9)  the  multiplier  is  to  be  sought  for  the  second  portion;  that  is,  for  dividend 
4  and  divisor  9;  being  the  former  divisor  and  dividend  reversed:  wherefore  multiplier  and  quo- 
tient will  here  be  transposed ;  and  will  answer  for  the  affirmative  additive :  and  the  series  now 

becomes  2 
2 
3 

6     Multiplier. 
3     Quotient. 

But  the  quotient  of  the  first  portion  of  the  dividend  (27)  after  multiplication  by  this  multiplicator, 
will  be  the  quotient  (3)  of  the  simple  dividend  taken  into  the  multiplicator  (6);  which,  as  is  appa- 
rent, is  the  term  of  the  series  next  beneath  it:  to  which  add  the  quotient  of  the  second  portion, 
which  is  last  term  in  the  series,  and  the  sum  is  the  entire  quotient  (21).  And  the  lowest  term  (3), 
being  of  no  further  use,  may  be  now  expunged :  as  is  directed  accordingly  (§  56).    Thus  the  series 

now  stands     2 
2 
21     Quotient. 
6    Multiplier. 


PULVERIZER. 


159 


their  respective  abraders,  the  residues  will  be  the  true  quotient  and  multi- 
plier.' _ 

The  next  step  is  to  fiml  the  multiplier  and  quotient  (the  additive  being  still  the  same)  for  the 
next  preceding  dividend  and  divisor;  viz.  71  and  31  :  and  here  the  dividend  consists  of  two  parts 
62  and  9  ;  to  the  last  of  which  only  the  multiplier  needs  to  be  adapted  ;  viz.  to  dividend  9  and  di- 
visor 31 ;  which  again  are  the  former  divisor  and  dividend  inverted:  wherefore  the  multiplier  and 
quotient  are  here  also  transposed;  and  the  quotient  of  the  first  portion  is  to  be  added  :  and  is  the 
quotient  (2)  of  the  simple  dividend  taken  into  the  multiplier  (21)  the  two  contiguous  terms  in  the 
series.  The  entire  quotient  therefore  is  48  answering  to  the  same  additive  but  negative:  and  the 
lowest  term  being  no  longer  required  may  now  be  rejected:  the  series  consequently  exhibits 

2 
48     Quotient. 
21     Multiplier. 
Lastly,  to  find  the  multiplier  and  quotient  for  the  next  superior,  which  are  the  final  dividend  and 
divisor  173  and  71-     Taking  the  dividend  as  composed  of  142  and  31  ;  and  seeking  a  multiplier 
which  will  answer  for  the  second  portion  31  with  the  divisor  71  ;  the  multiplier  and  its  quotient  are 
the  former  transposed:  and  the  entire  quotient  is  completed  by  adding  the  product  of  the  upper 
terms  of  the  series,  (and  answers  to  the  same  additive  but  affirmative) ;  after  which  the  lowest  term 
is  of  no  further  use  :  and  the  series  is  now  reduced  by  its  rejection  to  two  terms,  viz. 

117     Quotient. 
48     Multiplier. 

Thus,  according  to  the  tenor  of  the  rule,  the  work  is  to  be  repeated  as  many  times  as  there  are 
quotients  of  the  reciprocal  division ;  that  is,  until  two  terms  remain  (§  56).  In  all  these  operations, 
except  the  first,  the  multiplier  is  last  term  but  one  in  the  series;  and  the  quotient  of  the  second 
portion  of  the  dividend  is  the  last.  But,  in  the  first  operation,  there  is  no  quotient  of  a  second  por- 
tion to  be  added.  Therefore,  for  the  sake  of  uniformity  in  the  precept,  a  cipher  is  directed  to  be 
added  at  the  foot  of  the  series  (§  55),  that  the  multiplier  may  always  be  penultimate. 

If  the  multiplier  be  increased  by  the  addition  of  any  multiple  of  the  -tiivisor,  the  corresponding 
quotient  will  be  augmented  by  an  equi-raultiple  of  the  dividend  (§  64);  and,  in  like  manner,  if  the 
multiplier  be  lessened  by  subtraction  of  any  multiple  of  the  divisor,  the  quotient  is  diminished  by 
the  like  multiple  of  the  dividend.  Wherefore  it  is  directed  to  divide  the  pair  of  numbers  remain- 
ing in  the  series,  by  the  dividend  and  divisor,  and  the  remainders  are  the  quotient  and  multiplier 
in  their  least  terras.    (§  56.)  CiifsiiN. 

'  The  multiplier  for  the  last  dividend,  being  put  equal  to  the  additive,  is  adapted,  as  has  been 
observed,  (see  preceding  note,)  to  a  negative  additive ;  and  thence  proceeding  upwards,  the  multi- 
plier and  quotient,  which  are  transposed  at  each  step,  are  alternately  adapted  to  positive  and  nega- 
tive additives;  that  is,  at  the  uneven  steps  to  a  negative  one;  and  at  the  even,  to  a  positive  one. 
If  then  the  number  of  dividends,  or,  which  is  the  same,  that  of  the  quotients  of  reciprocal  division, 
be  even,  the  multiplier  and  corresponding  quotient  are  adapted  to  a  positive  additive;  if  it  be  odd, 
they  are  so  to  a  negative  one.  In  the  latter  case,  therefore,  the  complement  of  each  to  the  divisor 
and  dividend  respectively,  is  taken,  to  convert  them  into  multiplier  and  quotient  adapted  to  an 
affirmative  additive.  For  the  dividend,  being  multiplied  by  the  divisor  and  divided  by  the  same, 
hu  DO  remainder,  and  the  quotient  is  equal  to  the  dividend:  therefore  when  it  is  multiplied  by  a 


160  VIJ'A-GAN'ITA. 

58.  The  multiplier  is  also  found  by  the  method  of  the  pulverizer,  the 
additive  quantity  and  dividend  being  either  reduced  by  a  common  measure, 
[or  used  unreduced.]'  But,  if  the  additive  and  divisor  be  so  reduced,  the 
multiplier  found,  being  multiplied  by  the  common  measure,  is  the  true  one.* 

59.  The  multiplier  and  quotient,  as  found  for  an  additive  quantity,  being 
subtracted  from  their  respective  abraders,  answer  for  the  same  as  a  subtrac- 
tive  quantity.'  Those  deduced  from  an  affirmative  dividend,  being  treated 
in  the  same  manner,  become  the  results  of  a  negative  dividend.* 

60.  A  half  stanza.  The  intelligent  calculator  should  take  a  like  quo- 
tient [of  both  divisions]  in  the  abrading  of  the  numbers  for  the  multiplier 
and  quotient  [sought].' 

number  less  than  the  divisor,  and  separately  by  the  complement  of  this  maltiplier  to  the  divisor, 
both  products  being  divided  by  the  divisor,  should  the  one  have  a  positive  remainder,  the  other  will 
want  just  as  much  to  complete  the  amount  of  the  divisor ;  and  the  quotient  of  the  one  added  to 
that  of  the  other  [completed]  will  be  equal  to  the  dividend.  Wherefore,  if  the  quotient  and  mul- 
tiplier for  a  negative  additive  be  subtracted  from  their  respective  abraders,  (the  dividend  and  divi- 
sor,) the  differences  will  be  the  quotient  and  multiplier  for  a  positive  additive,  and  conversely. 
(§  57  and  59).  Crishi^. 

*  Gan'es'a  on  Lildvati. 

*  The  quotient  at  the  same  time  found  will  be  the  true  one. — GAy'.onLil.  In  the  former  instance^ 
the  quotient  as  found  was  to  be  multiplied  by  the  common  measure. — Ibid.  If  the  dividend  and 
additive  be  abridged,  while  the  divisor  remains  unchanged,  it  is  plain,  that  the  quotitnt  will  be  an 
abridged  one,  and  must  be  multiplied  by  the  common  measure  to  raise  the  quotient  for  the  original 
numbers.  In  like  manner,  if  the  divisor  and  additive  be  reduced  to  least  terms,  while  the  dividend 
is  retained  unaltered,  the  multiplier  thence  deduced  must  be  taken  into  the  common  measure. 
If  separate  common  measures  be  applicable  to  both,  viz.  dividend  and  additive,  the  multiplier  and 
quotient,  as  thence  found  in  an  abridged  form,  must  be  multiplied  by  the  common  measures  respec- 
tively. Crishn.  on  Vij. 

Su'byada'sa  directs  the  multiplier  alone  to  be  found  by  this  abbreviated  method,  and  then  to 
use  the  multiplier  thence  deduced  for  finding  the  quotient.     See  Su'r.  on  Lil. 

3  See  the  beginning  of  note  (')  to  §  56;  and  the  note  (')  to  §  57.  See  also  the  author's  remark 
after  §  67. 

A  change  of  the  sign  in  the  dividend  has  the  like  effect  on  the  results;  and  the  complement  of 
the  multiplier  to  the  divisor,  and  that  of  the  quotient  to  the  dividend,  are  the  multiplier  and  quo- 
tient adapted  to  the  dividend  with  an  altered  sign.     See  the  sequel  of  this  stanza.     §  59. 

*  This  second  half  of  the  stanza  is  not  inserted  in  the  Lildvati,  Crishn'a,  the  commentator  of 
the  Vija-Ganita,  notices  with  censure  a  variation  in  the  reading  of  the  text ;  "  Those  deduced  from 
a  negative  dividend,  being  treated  in  the  same  manner,  become  the  results  of  a  negative  divisor." 

'  The  rule  is  applicable  when  the  additive  quantity  exceeds  the  dividend  and  divisor. 


PULVERIZER.  161 

•  61.  But  the  multiplier  and  quotient  may  be  found  as  before,  the  additive 
quantity  being  [first]  abraded  by  the  divisor;  the  quotient,  however,  must 
have  added  to  it  the  quotient  obtained  in  the  abrading  of  the  additive. 
But,  in  the  case  of  a  subtractive  quantity,  it  is  subtracted. 

62.'  Or  the  dividend  and  additive  behig  abraded  by  the  divisor,  the  mul- 
tiplier may  thence  be  found  as  before;  and  the  quotient  from  it,  by  multi- 
plying the  dividend,  adding  the  additive,  and  dividing  by  the  divisor/ 

63.  If  there  be  no  additive  quantity,  or  if  the  additive  be  measured  by 
the  divisor,  the  multiplier  may  be  considered  as  cipher,  and  the  quotient  as 
the  additive  divided  by  the  divisor.' 

64.  Haifa  stanza.     The  multiplier  and  quotient,  being  added  to  their 


*  This  stanza,  omitted  in  the  greatest  part  of  the  collated  copies  of  the  LU&vati  and  by  most  of 
its  commentators,  occurs  in  all  copies  of  the  Vija-gaiiita,  and  is  noticed  by  the  commentators  of  the 
algebraic  treatise. 

*  If  the  divisor  be  contained  in  the  additive,  this  is  abraded  by  it,  and  the  remainder  is  employed 
as  a  new  additive  (§6l).  Here  the  additive  is  composed  of  two  portions  or  terms:  one  a  multiple 
of  the  divisor;  the  other  the  remainder  or  new  additive  :  from  the  latter  the  multiplier  is  found; 
such,  that,  multiplying  the  dividend  by  it,  and  adding  the  reduced  additive,  the  sum,  divided  by  the 
divisor,  yields  no  remainder.  The  other  portion  of  the  additive,  being  a  multiple  of  the  divisor,  of 
course  yields  none;  but  the  quotient  is  increased  by  as  many  times  as  the  divisor  is  contained  in  it, 
if  it  be  positive ;  or  reduced  by  as  much,  if  it  be  negative. 

If  both  dividend  and  additive  contain  the  divisor,  abrade  both  by  it,  and  use  the  remainder  as 
dividend  and  additive:  whence  find  the  multiplier:  which  will  be  the  same  as  for  the  whole  num- 
bers: and  the  proof  is  similar,  grounded  on  considering  the  dividend  as  composed  of  two  portions. 
The  quotient,  however,  is  regularly  deduced  by  the  process  at  large  of  multiplying  the  dividend  by 
the  multiplier,  adding  the  additive,  and  dividing  by  the  divisor  (§  62).  Or  it  may  be  deduced  from 
the  quotient  that  is  found  with  the  multiplier,  by  adding  to  that  quotient,  or  subtracting  from  it, 
the  sum  or  the  difference  (according  as  the  additive  was  positive  or  negative)  of  the  dividend  taken 
into  the  multiplier  and  the  additive,  both  divided  by  the  divisor.  This  last  mode  is  unnoticed  by 
the  author,  being  complex.  CafsHN. 

'  If  the  additive  be  nought,  multiply  the  dividend  by  nought,  the  product  is  nought,  which  being 
divided  by  the  divisor,  the  quotient  is  nought,  and  no  remainder.  If  the  additive  be  a  multiple  of 
the  divisor,  multiply  the  dividend  by  nought,  the  product  is  nought;  and  the  operation  is  confined 
to  the  division  of  the  additive  by  the  divisor.  Being  a  multiple  of  it,  there  is  no  remainder;  and 
jhe  quotient  of  this  division  is  the  quotient  sought.  CufsHrf, 


162  VUA-GAN'ITA.  Chapter  II. 

respective  [abrading]  divisors  multiplied  by  assumed  numbers,'  become  mani- 
fold.* 

65.  Example.  Say  quickly,  mathematician,  what  is  that  multiplier,  by 
which  two  hundred  and  twenty-one  being  multiplied,  and  sixty-five  added 
to  the  product,  the  sum  divided  by  a  hundred  and  ninety-five  becomes  cleared 
(giving  no  residue)? 

Statement:     Dividend  221       Ajr*.-      /?*- 

D,  „_     Additive  65. 
ivisor      195 

Here  the  dividend  and  divisor  being  divided  reciprocally ;  the  dividend, 
divisor  and  additive,  reduced  to  their  least  terms  by  the  last  of  the  remain- 
ders 13,  become  Dividend    17      ajj-*.-      r 
'  T\-  •  t^     Additive  5. 

Divisor       15 

The  reduced  dividend  and  divisor  being  mutually  divided,  and  the  quo- 
tients put  one  under  the  other,  the  additive  under  them,  and  cipher  at  the 
bottom,  the  series  which  results  is     1 

7 
5 
0 
Multiplying  by  the  penult  the  number  above  it  and  proceeding  as  di- 
rected [§  56],  the  two  quantities  obtained  are  40 

35 

These  being  abraded  by  the  reduced  dividend  and  divisor  17  and  15,  the 
quotient  and  multiplier  are  found  6  and  5.  Or,  adding  to  them  arbitrary 
multiples  of  their  abraders,  the  quotient  and  multiplier  are  23,  20;  or  40, 
35,  &c. 

66.  Example.     If  thou  be  expert  in  the  investigation  of  such  questions, 

'  To  arbitrary  multiples  of  the  divisors  used  in  abrading  the  pair  of  terms,  from  which  they  are 
deduced  as  residues  of  a  division ;  in  other  words,  multiples  of  the  reduced  dividend  and  divisor 
which  had  been  used  as  divisors  of  the  pair  of  terras. 

*  Additive  apart,  if  the  multiplier  be  equal  to  a  multiple  of  the  divisor,  the  quotient  will  be  an 
equimultiple  of  the  dividend.  Wherefore,  if  additive  be  null,  the  multiplier  is  cipher  (§  63)  witk 
or  without  a  multiple  of  the  divisor  added;  and  the  corresponding  quotient  will  be  cipher  with  a 
like  multiple  of  the  dividend :  and  generally,  the  multiplier  and  quotient  having  been  found  for 
any  given  additive,  dividend  and  divisor,  equimultiples  of  the  divisor  and  dividend  may  be  respec- 
tively added  to  the  multiplier  and  quotient.     Sec  Crishn. 


PULVERIZER.  163 

tell  me  the  precise  multiplier,  by  which  a  hundred  being  multiplied,  with 
ninety  added  to  the  product  or  subtracted  from  it,  the  sum  or  the  difference 
may  be  divisible  by  sixty-three  without  a  remainder. 

Statement:     Dividend  100     ajjv  t ,.     4.-      ^n 

TA-  •  cc     Additive  or  subtractive  90. 

Divisor        §3 

Here  the  series  is     1     And  the  quotient  and  multiplier  found  as  before 

1  are  30  and  18. 

1 

2 

2 

1 

90 
0 

Or  the  dividend  and  additive  being  reduced  by  the  common  measure  ten, 

the  statement  is  Dividend  10    ^^ 
Divisor      63 

The  series  is  0    And  the  multiplier  comes  out  45.     The  quotient  is  here  not 
6 
3 

9 
0 

to  be  taken.  As  the  quotients  in  this  series  are  an  odd  number,  the  multi- 
plier 45  is  to  be  subtracted  from  its  abrader  63;  and  the  multiplier  thus 
found  is  the  same  18.  The  dividend  being  multiplied  by  that  multiplier, 
and  the  additive  quantity  being  added,  and  the  sum  divided  by  the  divisor, 
the  quotient  found  is  30. 

Or  the  divisor  and  additive  are  reduced  by  the  common  measure  nine: 

Dividend  100  Ajditiyejo  The  series  then  is  14  The  multiplier  thence 
Divisor  7  '  3 

10 
0 
deduced  is  2:  which  multiplied   by   the  common  measure  9,  makes   the 
same  18. 

Or,  the  dividend  and  additive  are  reduced,  and  further  the  divisor  and  ad- 
ditive, by  common  measures.     Dividend  10      .  i  v.- 

Divisor       7     ^'''^''^^^   ^' 
Proceeding  as  before,  the  series  is  1     Hence  the  multiplier  is  found  2; 

2 
1 
0  "^' 

Y  2 


104  VIJA-GANITA.  Chapter  II. 

which  multiplied  by  the  common  measure  of  the  divisor  and  additive  (viz.  9) 
becomes  the  same  18.  Whence,  by  multiplication  and  division,  the  quo- 
tient is  found  30. 

Or,  adding  to  the  quotient  and  multiplier  arbitrary  multiples  of  their  divi- 
sors, the  (juotient  and  multiplier  are  130,  81 ;  230,  144,  &c. 

67.  Example.  Tell  me,  mathematician,  the  multipliers  severally,  by 
which  the  negative  number  sixty  being  multiplied,  and  three  being  added  to 
the  product,  or  subtracted  from  it,  the  sum  or  difference  may  be  divided  by 
thirteen  without  remainder.* 

Statement:     Dividend  60      ajv*.-      /         1*      >.•    \ » 
^^■   •  ,0     Additive  (or  subtractive)  3. 

Divisor       13  ^  ^ 

Found  as  before*  for  an  affirmative  dividend  and  positive  additive  quantity, 
the  multiplier  and  quotient  arc  1 1  and  5 1 .  These,  subtracted  from  their 
abraders  13,  60,  give  for  a  negative  dividend  and  positive  additive  [§  59]  2,  9- 
Thcse  again,  subtracted  from  their  abraders  1 3,  60,  give  for  a  negative  divi- 
dend and  negative  additive  11,  51.  "  Those  (the  multiplier  and  quotient) 
deduced  from  an  affirmative  dividend,  being  treated  in  the  same  manner, 
become  results  of  a  negative  dividend."  (§  59)-  This  has  been  by  me  spe- 
cified to  aid  the  comprehension  of  the  dull:  for  it  followed  else  from  the 
rule,  "  The  multiplier  and  quotient,  as  found  for  an  additive  quantity,  being 
subtracted  from  their  respective  abraders,  answer  for  the  same  as  a  subtrac- 
tive quantity  :"  [ibid.]  since  the  addition  of  negative  and  affirmative  is  pre- 
cisely subtraction.  Accordingly  taking  the  dividend,  divisor  and  additive 
as  all  positive,  the  multiplier  and  quotient  are  to  be  found  :  they  are  results 
of  an  additive  quantity.  Subtracting  them  from  their  abraders,  they  aie 
to  be  rendered  results  of  a  negative  quantity. 

If  either  the  dividend  or  its  divisor  become  negative,  the  quotients  of  re- 
ciprocal division  would  be  to  be  stated  as  negative:  which  is  a  needless  trou- 
ble.    Were  it  so  done,  one  (either  dividend  or  divisor)  becoming  negative, 

*  This  stanza  differs  from  one  in  the  Lildvati  (§  257)  in  the  amount  of  the  additive  or  subtractive 
quantity;  and  in  specifying  the  sign  of  the  dividend.  It  comprises  two  examples:  the  additive 
being  either  negative  or  positive. 

*  The  series  is^^rt-^^-icoo;  whence  the  pair  of  numbers  @  "^  :  which  abraded  give  oi  w  ; 
and,  the  quotients  being  uneven  in  number,  they  are  subtracted  from  their  abraders  %  2  and  yield 
the  quotient  and  multiplier  51,  II,  CaisuK. 


PULVERIZER.  165 

there  would  be  error  in  the  quotient  [and  multipher']  under  the  last  men- 
tioned rule  (§  64;. 

68.  Example.  By  what  number  being  multiplied  will  eighteen,  having 
ten  added  to  the  product,  or  ten  subtracted  from  it,  yield  an  exact  quotient, 
being  divided  by  the  negative  number  eleven?* 

Statement .     Dividend  1 8     ^^^-^-^^  ^^^  subtractive)  1 0. 
Divisor      1 1 

Here  the  divisor  being  treated  as  affirmative,  the  multiplier  and  quotient 
are  8,  14.  The  divisor  being  negative,  they  are  the  same:  but  the  quotient 
must  be  considered  to  have  become  negative,  since  the  divisor  is  so;  8,  14. 
The  same,  being  subtracted  from  their  abraders,  become  the  multiplier  and 
quotient  for  the  negative  additive ;  3,  4. 

69.  Example.  What  is  the  multiplier,  by  which  five  being  multiplied, 
and  twenty-three  added  to  the  product,  or  subtracted  from  it,  the  sum  or  dif- 
ference may  be  divided  by  three  without  remainder? 

Statement:     Dividend  5      a  1  i-.-      /         1.      ^'     \/,o 
T-,.  .  _     Additive  (or  subtractive)  23. 

Divisor      3  ^  ^ 

Here  the  series  is     1     and  the  pair    of  numbers  found  as  before  is  46 
1  23 

23 
0 

These  are  to  be  abraded  by  the  dividend  and  divisor.  The  lower  number 
being  abraded  by  three,  the  quotient  is  seven.  The  upper  one  being  so  by 
five,  the  quotient  would  be  nine.  This,  however,  is  not  accepted:  but,  un- 
der the  rule  for  taking  a  like  quotient  (§  60),  seven  only.  Thus  the  multi- 
plier and  quotient  are  found  2,  11.  By  the  former  rule  (§  59)  the  multiplier 
and  quotient  answering  to  the  same  as  a  negative  quantity  come  out  1,  6. 
Added  to  arbitrary  multiples  of  their  abraders  (§  63),  so  as  the  quotient  ma}' 
be  affirmative,  the  multiplier  and  quotient  are  7,  4,  &c.  So  in  every  [similar] 
case. 

Or,  applying  another  rule  (§61),  the  statement  is  Divd.  5     Abraded 

Divr.  3     Additive 

•  The  error  would  be  in  the  multiplier  as  well  as  the  quotient.  CaiiHK. 

?  An  example  not  inserted  in  the  LUdvati;  being  algebraic. 


166  VI'JA-GANITA.  Chapter  11. 

The  multiplier  and  quotient  hence  found  as  before  are  2,  4.  Tliese,  sub- 
tracted from  their  respective  divisors,  give  1,  1  ;  as  answering  to  the  subtrac- 
tive  quantity.  The  quotient  obtained  iu  abrading  the  additive  being  added, 
the  result  is  2,  11,  answering  to  the  additive  quantity;  or  subtraction  being 
made,  1,  6,  answering  to  the  subtractive;  or  (adding  thereto  twice  the  divi- 
sors, to  obtain  an  affirmative  quotient,)  7,  4. 

70.  Example.  Tell  me,  promptly,  n)athematician,  the  multiplier,  by 
which  five  being  multiplied  and  added  to  cipher,  or  added  to  sixty-five,  the 
division  by  thirteen  shall  in  both  cases  be  without  remainder. 

Statement:  Dividends  ajjv  « 
T^.  •  -  _  Additive  0. 
Divisor   1 3 

There  being  no  additive  quantity,  the  multiplier  and  quotient  are  0,  0;  er 

13,5. 

Statement:     Dividend    5     Additive  65. 
Divisor      13 

By  the  rule  (§  63)  the  multiplier  is  cipher,  and  the  quotient  is  the  additive 

divided  by  the  divisor,  0,  5  ;  or  13,  10,  &c. 

71.  Rule  for  a  constant  pulverizer:'  Unity  being  taken  for  the  additive 
quantity,  or  for  the  subtractive,  the  multiplier  and  quotient,  which  may  be 
thence  deduced,  being  severally  multiplied. by  an  arbitrary  additive  or  sub- 
tractive,*  and  abraded  by  the  respective  divisors,  will  be  the  multiplier  and 
quotient  for  such  assumed  quantity.' 

In  the  first  example  (§  65)  the  statement  of  the  reduced  dividend  and  divi- 
sor, with  additive  unity,  is  Dividend  17  Additive  1.    Here  the  multiplier  and 

Divisor      15  '^ 

*  A  rule  which  is  of  especial  use  in  astronomy. — Crishn.  Su'r.  See  Algebra  of  Braiime- 
GUPTA,  §  9 — 12,  and  §  35. 

*  If  the  arbitrary  additive  be  positive,  the  multiplier  and  quotient,  as  found  for  additive  unity,, 
are  to  be  multiplied  by  the  arbitrary  affirmative  additive.  If  it  be  negative,  those  found  for  sub- 
tractive  unity  are  to  be  multiplied  by  the  arbitrary  subtractive,  or  negative  additive.      Crishn. 

'  The  rule  may  be  explained  by  that  of  proportion :  if  unity  as  the  additive  (or  subtractive) 
quantity  give  this  multiplier  and  this  quotient,  what  will  the  assumed  additive  (or  subtractive) 
quantity  yield  ?  Crisbw. 


CONSTANT    PULVERIZER.  l67 

quotient  are  found  7,  8.  These,  multiplied  by  an  assumed  additive  five,  and 
abraded  by  the  respective  divisors,  give  for  the  additive  5,  the  multiplier  and 
quotient  5,  6. 

Next,  unity  being  the  subtractive  quantity,  the  multiplier  and  quotient, 
thence  found,  are  8,  9.  These,  multiplied  by  five  and  abraded  by  their  re- 
spective divisors,  give  10,  11.     So  in  every  [similar]  case. 

Of  this  method  of  investigation  great  use  is  made  in  the  computation  of 
planets.'     On  that  account  something  is  here  said  [by  way  of  instance.] 

72.  Let  the  remainder  of  seconds  be  made  the  subtractive  quantity,  sixty 
the  dividend,  and  terrestrial  days  the  divisor.  The  quotient  deduced  there- 
from will  be  the  seconds;  and  the  multiplier  will  be  the  remainder  of  mi- 
nutes. From  this  again  the  minutes  and  remainder  of  degrees  are  found: 
and  so  on  upwards.  In  like  manner,  from  the  remainder  of  exceeding 
months  and  deficient  days,  may  be  found  the  solar  and  lunar  days.* 

'  It  is  less  employed  in  popular  questions,  where  the  dividend  and  divisor  are  variable.  But, 
in  astronomy,  where  additive  or  subtractive  quantities  vary,  while  the  dividend  and  divisor  are  con- 
stant, this  method  is  in  frequent  use.     See  Crishn. 

*  By  the  rule  for  finding  the  place  of  a  planet  {Siromadi,  §  .50)  the  whole  number  of  elapsed  days, 
multiplied  by  the  revolutions  in  the  great  period  calpa,  and  divided  by  the  number  of  terrestrial 
days  in  a.  calpa,  gives  the  past  revolutions:  the  residue  is  the  remainder  of  revolutions;  which,  mul- 
tiplied by  twelve  and  divided  by  terrestrial  days  in  a  calpa,  gives  the  signs:  the  balance  is  remain- 
der of  signs;  and  multiplied  by  thirty,  and  divided  by  terrestrial  days,  gives  the  degrees:  the  over- 
plus is  remainder  of  degrees  ;  and  multiplied  by  sixty,  and  divided  by  terrestrial  days,  gives  minutes: 
the  surplus  is  remainder  of  minutes ;  and  this  again,  multiplied  by  sixty,  and  divided  by  terrestrial 
days,  gives  seconds;  and  what  remains  is  residue  of  seconds.  Now,  by  inversion,  to  find  the  pla- 
net's place  from  the  remainder  of  seconds:  if  the  remainder  of  seconds  be  deducted  from  the 
remainder  of  minutes  multiplied  by  sixty,  then  the  difference  divided  by  terrestrial  days  will  yield 
no  residue  :  but  the  remaiiider  of  minutes  being  unknown,  its  multiple  by  sixty  is  so  a  fortiori: 
however,  remainder  of  minutes  multiplied  by  sixty,  and  sixty  multiplied  by  remainder  of  minutes, 
are  equal;  for  there  is  no  difference  whether  quantities  be  multiplicator  or  multiplicand  to  each 
other.  Therefore  sixty,  multiplied  by  remainder  of  minutes,  and  having  remainder  of  seconds  sub- 
tracted from  the  product,  will  be  exactly  divisible  by  terrestrial  days  without  residue;  and  the 
quotient  will  be  seconds.  Now,  in  the  problem,  sixty  and  the  remainder  of  seconds  [as  also  the 
terrestrial  days  in  a  calpa]  are  known  :  and  thence  to  find  the  remainder  of  minutes,  a  multiplier  is 
to  be  sought,  such  that  sixty  being  multiplied  by  it,  and  the  subtractive  quantity  (remainder  of  se- 
conds) being  taken  from  the  product,  the  difference  may  be  divisible  by  terrestrial  days  without 
residue;  and  this  precisely  is  matter  for  iuvestigation  of  (cuiiaca)  the  pulverizing  multiplier. 


168  VrJA-GAN'ITA.  Chapter  II. 

The  finding  of  the  [place  of  the]  planet  and  the  elapsed  days,  from  the 
remainder  of  seconds  in  the  planet's  place,  is  thus  shown.  It  is  as  follows. 
Sixty  is  there  made  the  dividend;  terrestrial  days,  the  divisor;  and  the  re- 
mainder of  seconds,  the  subtractive  quantity  :  with  which  the  multiplier  and 
quotient  are  to  be  found.  The  quotient  will  be  seconds;  and  the  multiplier, 
the  remainder  of  minutes.  From  this  remainder  of  minutes  taken  [as  the 
subtractive  quantity]  the  quotient  deduced  will  be  minutes;  and  the  multi- 
plier, the  remainder  of  degrees.  The  residue  of  degrees  is  next  the  subtrac- 
tive quantity;  terrestrial  days,  the  divisor;  and  thirty,  the  dividend:  the 
quotient  will  be  degrees;  and  the  multiplier,  the  remainder  of  signs.  Then 
twelve  is  made  the  dividend;  terrestrial  days,  the  divisor;  and  the  remainder 
of  signs,  the  subtractive  quantity  :  the  quotient  will  be  signs;  and  the  multi- 
plier, the  remainder  of  revolutions.  Lastly,  the  revolutions  in  a  calpa  become 
the  dividend;  terrestrial  days,  the  divisor;  and  the  remainder  of  revolutions, 
the  subtractive  quantity :  the  quotient  will  be  the  elapsed  revolutions;  and 
the  multiplier,  the  number  of  elapsed  days.  Examples  of  this  occur  [in  the 
Siromam]  in  the  chapter  of  the  [three]  problems.' 

In  like  manner  the  exceeding  months  in  a  calpa  are  made  the  dividend; 
solar  days,  the  divisor;  and  the  remainder  of  exceeding  months,  the  subtrac- 
tive quantity:  the  quotient  will  be  the  elapsed  additional  months;'  and  the 
multiplier,  the  elapsed  solar  days.  So  the  deficient  days  in  a  j/uga"  are  made 
the  dividend;  lunar  days,  the  divisor;  and  the  remainder  of  deficient  days^ 
the  subtractive  quantity:  the  quotient  will  be  the  elapsed  fewer  days;*  and 
the  multiplier,  the  elapsed  lunar  days. 

73.  Rule  for  a  conjunct  pulverizer:'  If  the  divisor  be  the  same,  and  the 
multipliers  various  [two  or  more'];  then,  making  the  sum  of  those  multi- 

'  Prasn&'d!hyAya;  meaning  the  Triprasnd'd'hyiya  of  the  astronomical  portion  of  the  Siiomaili. 

*  The  excess  of  lunar  above  solar  months. 

*  Yuga  is  here  an  error  of  the  transcriber  for  calpa;  or  has  been  introduced  by  the  author  to 
intimate,  that  the  method  is  not  restricted  to  time  calculated  by  the  calpa,  but  also  applicable 
when  the  calculation  is  by  the  yvga  or  any  other  astronomical  period.  Cri'shn, 

This  reading,  however,  does  not  occur  in  copies  of  the  LiMrati,  though  it  do  in  all  collated  one* 
of  the  Vija-ganita :  nor  is  it  noticed  by  the  commentators  of  the  LiUvati, 

*  Difference  between  elapsed  lunar  and  terrestrial  days. 

*  See  LU&vati,  §  265. 

*  Crishn.  on  Vij.  and  Gan.  on  Lil, 


CONJUNCT    PULVERIZER.  169 

pliers  the  dividend,  and  the  sum  of  the  remainders  a  single  remainder ;  and 
applying  the  foregoing  method  of  investigation,  the  precise  multiplier  so 
found'  is  denominated  a  conjunct  one. 

74.  Example.  What  quantity  is  it,  which  multiplied  by  five,  and  di- 
vided by  sixty-three,  gives  a  residue  of  seven;  and  the  same  multiplied  by 
ten  and  divided  by  sixty-three,  a  remainder  of  fourteen  ?  declare  the  number. 

Here  the  sum  of  the  multipliers  is  made  the  dividend;  and  the  sum  of  the 
residues,  a  subtractive  quantity;  and  the  statement  is  Divd.  15  o   i  .  .      „, 

D£.rt    oUDtiaC.  J!  1  • 
ivr.  63 

Proceeding  as  before,  the  multiplier  is  found  14.  It  is  precisely  the  num- 
ber required. 

'  As,  putting  the  multiplicand  for  dividend,  the  multiplier  is  found  by  the  investigation  which 
is  the  subject  of  this  chapter;  so,  making  the  multiplicator  dividend,  the  multiplier  found  by  the 
investigation  is  multiplicand,  in  like  manner  as  sixty  is  made  dividend,  in  the  foregoing  instance 
(§  72).  Then,  as  the  given  quantity,  being  lessened  by  subtraction  of  an  amount  equal  to  the  resi- 
due of  the  division  of  it  by  the  divisor  after  multiplication  by  one  of  the  multiplicators,  becomes 
exactly  divisible;  so,  by  parity  of  reasoning,  it  docs,  when  lessened  by  the  subtraction  of  the 
respective  remainders,  which  the  whole  number  yields,  being  severally  multiplied  by  the  rest  of  the 
multiplicators  and  divided  by  the  divisor.  And  generally,  if  the  divisor  be  the  same,  then,  as  the 
quantity,  severally  multiplied  by  the  multiplicators  and  lessened  by  the  respective  remainders, 
becomes  exactly  divisible  by  the  divisor ;  so  it  does,  when,  being  severally  multiplied,  the  multi- 
ples are  added  together  and  the  sum  is  lessened  by  the  aggregate  of  remainders.  Now  the  quantity 
multiplied  by  the  sum  of  the  multiplicators  is  the  same  as  if  severally  multiplied  by  the  multipli- 
cators and  the  multiples  then  added  together.  Therefore  the  sum  of  the  multiplicators  is  taken 
for  a  multiplicator  [and  employed  as  a  dividend ;]  and  the  aggregate  of  the  remainders  is  received 
for  a  remiiinder  [and  employed  as  subtractive  or  additive.]  Crisiin. 


CHAPTER    III. 


AFFECTED    SQUARE.' 


SECTION  I. 

75 — 81.  Six  and  a  half  stanzas.  Rules  for  investigating  the  square- 
root  of  a  quantity  with  additive  unity :  Let  a  number  be  assumed,  and 
be  termed  the  "  least"  root.^  That  number,  which,  added  to,  or  sub- 
tracted from,  the  product  of  its  square  by  the  given  coefficient,''  makes 
the  sum   (or  difference)  give  a  square-root,    mathematicians  denominate 

'   Varga-pracrtli  or  Criti-pracrtti ;  from  varga  or  crtti,  square,  and  pracrHii,  nature  or  principle. 

'  This  branch  of  computation  is  so  denominated,  either  because  the  square  o[ y&vat  or  of  another 
symbol  is  (pracrtti)  the  subject  of  computation ;  or  because  the  calculus  is  concerned  with  the 
number  which  is  (pracriti)  the  subject  affecting  the  square  of  ^a  or  other  symbol.  The  number, 
that  is  (pracriti)  the  subject  in  respect  of  such  square,  is  intended  by  the  term.  It  is  the  mul- 
tiplier of  the  square  of  the  unknown:  and  therefore,  in  this  investigation  of  a  root,  the  multiplier 
of  the  square  is  signified  by  the  word  pracriti.'  Crisii^. 

See  §  185;  the  author's  own  comment  on  that  and  on  §  187  and  §  171.  In  one  place  ;»racrKi 
is  applied  by  him  to  the  square  affected  by  the  coefficient ;  in  the  other  it  is  declared  to  intend  the 
coefficient  affecting  the  square.  The  commentator  Su'ryada'sa  interprets  it  in  the  first  sense 
(note  on  §  195) ;  and  Crishn'a,  in  the  latter.     (Vide  supra). 

'  The  method  here  taught  subserves  the  solution  of  certain  problems  producing  quadratic  equa- 
tions that  involve  more  than  one  unknown  term.'  Crishn. 

*  Hras-uia,  canisM'ha,  or  laghu,  (mdla;)  the  "least"  root;  so  denominated  with  reference  to 
additive  quantities,  though  it  may  exceed  the  other  root,  when  the  quantity  is  subtractive  (a  ne- 
gative additive)  and  is  comparatively  large.     See  Crishn. 

*  Pracriti  or  guna ;  the  given  coefficient  (anca)  and  multiplier  (guiiaj  affecting  the  square. 
See  a  preceding  note,  and  Chap.  7. 


Section  I.  A  F  FECTE  D    SQUARE.  I71 

a  positive  or  a  negative  additive  ;*  and  they  call  that  root  the  "  greatest" 
one." 

76.  Having  set  down  the  "  least"  and  "  greatest"  roots  and  the  additive, 
and  having  placed  under  them  the  same  or  others,'  in  the  same  order,  many 
roots  are  to  be  deduced  from  them  by  composition.*  Wherefore  their  com- 
position is  propounded. 

77.  The  "  greatest"  and  "  least"  roots  are  to  be  reciprocally  multiplied 
crosswise  ;^  and  the  sum  of  the  products  to  be  taken  for  a  least  root.  The 
product  of  the  two  [original]  "  least"  roots  being  multiplied  by  the  given 
coefficient,  and  the  product  of  the  "greatest"  roots  being  added  thereto,  the 
sum  is  the  corresponding  greatest  root;  and  the  product  of  the  additives 
will  be  the  [new]  additive. 

78.  Or  the  difference  of  the  products  of  the  multiplication  crosswise  of 
greatest  and  least  roots  may  be  taken  for  a  "  least"  root :  and  the  difference 
between  the  product  of  the  two  [original]  least  roots  multiplied  together 
and  taken  into  the  coefficient,  and  the  product  of  the  greatest  roots  multi- 
plied together,  will  be  the  corresponding  "  greatest"  root :  and  here  also  the 
additive  will  be  the  product  of  the  two  [original]  additives. 

79-     Let  the  additive  divided  by  the  square  of  an  assumed  number,  be  a 

'  Cshepa,  an  additive  either  positive  or  negative  :  a  quantify  superinduced,  either  affirmative  or 
negative,  and  consequently  additive  or  subtractive.  See  chap.  2,  §53  et  passim.  Li/,  ch.  11, 
§  24S. 

*  /j/t*^<'Aa,  the  "  greatest"  root,  contradistinguished  from  Canisht'ha,  the  least  root :  although 
it  may  in  some  cases  be  less,  when  the  cshipaca,  or  additive,  is  negative. — Crisun.  Provided 
this  subtractive  quantity  be  large  and  the  coeflicient  small. 

'  That  is,  other  roots  for  the  same  coefficient  affecting  the  square.  Crishn. 

♦  Bhdvand,  composition,  or  making  right*  by  combination.  It  is  twofold  :  1st.  yoga-bMvand, 
or  tam&ia-hMvani,  composition  by  the  sum  of  the  products  (§  77)  ;  2d.  antara-bMvani,  or  visesha- 
bMvani,  composition  by  the  difference  (§  78).  Recourse  is  had  to  the  first,  when  large  roots  are 
sought;  to  the  second,  when  small  are  required.  Crishn. 

'  Vajrdbhy'ixa,  multiplication  crosswise  or  zigzag.  From  vajra,  lightning  or  the  thunderbolt^ 
and  abhyha,  reciprocal  multiplication.     It  is  oblique  multiplication  (tiryag-gwiana), 

Si/a.  and  Crishn. 

•  Shivnt/ati,  Md'ha^arM  (makes  right).         Cslann. 

z  2 


172  VrJA-GAN'ITA.  Chapter  III. 

new  additive  ;  and  the  roots,  divided  by  that  assumed  number,  will  be  the 
corresponding  roots.  Or  the  additive  being  multiplied  [by  the  square],  the 
roots  must,  in  like  manner,  be  multiplied  [by  the  number  put]. 

80 — 81.  Or  divide  the  double  of  an  assumed  number  by  the  difference 
between  the  square  of  that  assumed  number  and  the  given  coefficient;  and 
let  the  quotient  be  taken  for  the  "  least"  root,  when  one  is  the  additive 
quantity ;  and  from  that  find  tlie  "  greatest"  root.  Here  [the  solutions  are] 
infinite,  as  well  from  [variety  of]  assumptions,  as  from  [diversity  of]  com- 
position.' 

'  The  principle  of  the  first  rule  (§  75,)  as  observed  by  the  commentator  Cri'shna-bhat'ta,  is 
too  evident  to  require  demonstration.  That  of  §  79  is  used  by  him  in  demonstrating  the  others, 
and  is  thus  given  :  A  square,  multiplied  or  divided  by  a  square,  yields  still  a  square.  If  both 
sides  of  the  equation  (L*.  coefT.  +  A  =  G')  be  multiplied  or  divided  by  the  square  of  any  assumed 
number,  equality  continues.  Now,  as  the  squares  of  the  "  leant"  and  "  greatest"  roots  are  here 
multiplied  by  the  square  of  the  assumed  number,  the  factor  of  those  roots  themselves  will  be  the 
simple  number  put. 

The  demonstration  of  §  77,  which  is  given  in  words  at  length,  joined  with  a  cumbrous  notation 
of  the  algebraical  expressions,  may  be  thus  abridged  :  To  distinguish  the  two  sets,  let  L,  G  and  A 
represent  one  set;  1,  g  and  a  the  other;  and  C  the  given  coefficient.*  Then,  under  §79.  putting 
g  for  the  assumed  number,  another  set  is  deduced  from  the  first,  L.g.G.g,  A.g'.  Whence  C.L'.g*+ 
A.g'=G'.g'.  Substitute  for  g' its  value  C.l'+a  ;  and  the  additive  A.g' becomes  A.Cl.'+A.a; 
and,  substituting  in  the  first  term  for  A  its  value  G'—C.L',  it  becomes  CGM'— C'.L.''l'  + A.a. 
Hence  the  equation  C.L'.g'  +  C.GM' — C'.LM'+A.a=G'.g';  whence,  transposing  the  negative 
term  and  adding  or  subtracting  SC.L.G.l.g;  the  result  is  C.(L.g4-l.G)'+A,a=(G.g+C.L.l)'.  See 
§78. 

The  concluding  rule  §  80 — 81  is  thus  proved  by  the  same  commentator:  '  Twice  an  assumed 
number  being  put  for  the  "  least"  root  (§  75)  its  square  is  four  limes  the  square  of  that  assumed 
number.  The  point  is  to  find  a  quantity  such,  that  being  added  to  this  quadruple  square  taken 
into  the  given  coefficient,  the  sum  may  be  a  square.  Now  the  difference  between  the  square  of 
the  sum  of  two  quantities  and  four  times  their  product  is  the  square  of  their  difference.  Therefore 
four  times  the  square  of  the  assumed  number,  multiplied  by  the  given  coefficient,  and  added  to 
the  square  of  the  difference  [between  the  square  of  the  assumed  number  and  the  coefficient,]  must 
of  course  give  a  square-root.  Thus  the  "  least"  root  is  twice  the  number  assumed  ;  and  the  addi- 
tive quantity  is  the  square  of  the  difference  between  the  square  of  the  assumed  number  and  the 
coefficient.  But,  by  the  condition  of  the  problem,  the  additive  quantity  must  be  unity.  Divide 
therefore,  under  §  70,  by  the  square  of  the  difference,  at  the  same  time  dividing  the  root  by  the 
simple  difference  between  the  square  of  the  assumed  number  and  the  given  coefficient.'    Cri'shn. 

•  Ckishka-biiatta  puts  the  aymbols  pro,  i  ca,  djyi,  i  csh(,  dwi  en,  dwijyi,  and  diet  ctlii,  initial  syllables  of  pnicn»i 
^aefficient  afiecting  the  square,  idya  first  and  dtnittya  second,  ctmiiht'ha  least, JyftAl'/io  greatest  (root)  and  ahifa  addit'ive. 


Section  I.  AFFECTED    SQUARE.  173 

82.  Example.  What  square,  multiplied  by  eight,  and  having  one 
added  to  the  product,  will  be  a  square?  Declare  it,  mathematician!  Or 
what  square,  multiplied  by  eleven,  and  having  one  added  to  the  product, 
will  be  a  square,  my  friend  ? 

Statement  on  Example  1st:     C  8     A  1. 

Here  putting  unity  for  the  assumed  "  least"  root,  the  "  greatest"  root  is 
three,  and  additive  one.     Statement  of  them  for  composition  : 

C  8     L  1     G  3     A  1 

11      g  3      a  1 

By  the  rule  [§  77]  the  first  "  least"  root  1,  multiplied  by  the  second 
"  greatest"  root  3,  gives  the  product  3.  The  second  "  least"  root,  by  the 
first  "  greatest,"  gives  the  like  product.  Their  sum  is  6.  Let  this  be  the 
"  least"  root.  The  product  of  the  two  "less"  roots  1,  being  multiplied  by 
the  given  coefficient  8,  and  added  to  the  product  of  the  two  "  greater" 
roots  9,  makes  17-  This  will  be  the  "  greater"  root.  The  product  of  the 
additives  will  be  the  additive  1. 

Statement  of  the  former  roots  and  additive,  with  these,  for  composition  : 

C  8     L  1     G    3     A  1 
1  6     g  17     a  1 

Here,  by  composition,  the  roots  are  found  L  35    G  99    A  1 ;  and  so  on, 

indefinitely,  by  means  of  composition. 

Statement  on  Example  2d  :     Putting  unity  for  the  assumed  "  least,"  and 
subtracting  two  from  the  square  of  that  multiplied  by  the  given  coefficient 
11,    the  "greater"  root   is    3.      Hence   the  statement  for  composition    is 
C  11     L  1     G  3     A  2 
1    1      g  3      a  'i 

Proceeding  as  before,  the  roots  for  additive  4  are  L6  G  20  A  4. 
Then,  by  the  rule  §  79j  putting  two  for  the  assumed  number,  the  roots  for 
unity  additive  are  found  L  3  G  10  A  1.  Hence,  by  composition  of  like 
sets,'  the  "  least"  and  "  greatest"  roots  are  found  Z  60  G  199  ^  1-  In  like 
manner,  an  indefinite  number  of  roots  may  be  deduced. 

'  TUya-bha-rana ;  the  combining  of  like  sets.  Whatever  may  have  been  the  additive  quantity 
lirst  found,  and  whether  it  were  positive  or  negative,  the  combination  of  lil<e  sets  raises  the  addi- 
tive to  a  square;  and  then,  under  §  79,  assuming  a  number  equal  to  the  root  of  that  square,  and 
dividing  the  additive  by  that  square,  the  additive  is  reduced  to  unity,  and  the  roots  answering  to 
it  are  found  by  division. 


174  VI'JA-GAN'ITA.  Chaptek  III. 

Or,  putting  unity  for  the  "  least"  root,  the  two  roots  for  additive  five  are 
found  L  1  G  4  A  5.  Whence,  by  composition  of  like  sets,  L  8  G  27 
A  25.  From  this,  by  §  79,  putting  five  for  the  assumed  number,  the  roots 
for  additive  unity  are  found  L  f    G  ^    A  I. 

Statement  of  these  with  the  preceding,  for  composition:  L3    G  10    Al 

1  f  g  V  a  1 
From  composition  by  the  sum,  roots  are  deduced  L  'f^    G  *f  *    A  1. 

Or,  under  rule  §  78  ;  from  composition  by  the  difference,  they  come  out 
L -^   Gf   A  \.     And  so  on,  in  numerous  ways. 

The  roots  for  unity  as  the  additive,  may  be  found  by  another  process,  un- 
der §  80.  Here,  putting  three  for  the  assumed  number,  and  proceeding  as 
directed,  the  "  least"  root  comes  out  6.  Viz.  assumed  number  3.  Its  square 
9.  Given  cocfl^cient  8.  Their  difference  1.  Twice  the  assumed  number 
6,  divided  by  that  difference,  is  6;  the  "  least"  root:  L  6.  Its  square  36; 
multiplied  by  the  given  coefficient  8,  is  288 ;  which,  with  one  added,  be- 
comes 289 ;  the  root  of  which  is  17,  the  "greatest"  root:   G  17- 

So,  in  the  second  example  likewise,  putting  three  for  the  assumed  num- 
ber, and  proceeding  as  directed,  the  roots  are  found  ;  L3    G  10    A  1. 

Thus,  by  virtue  of  [a  variety  of]  assumptions,  and  by  composition  either 
by  sum  or  diiference,  an  infinity  of  roots  may  be  found.* 

'  A  variety  of  additives  is  also  found:  but  it  is  not  noticed,  because  the  problem  is  restricted  to 
additive  unity.  Crisun. 


(     175     ) 


SECTION    II. 


83 — S6.  Rule  for  the  cyclic  method:^  (completion  of  stanza  81,  three 
stanzas,  and  half  another.)  Making  the  "  least"  and  "  greatest"  roots  and  ad- 
ditive,^ a  dividend,  additive  and  divisor,  let  the  multiplier  be  thence 
found.'  The  square  of  that  multiplier  being  subtracted  from  the  given  co- 
efficient, or  this  coefficient  being  subtracted  from  that  square,  (so  as  the  re- 
mainder be  small;*)  the  remainder,  divided  by  the  original  additive,  is  anew 
additive;  which  is  reversed  if  the  subtraction  be  [of  the  square]  from  the 
coefficient.'  The  quotient  corresponding  to  the  multiplier  [and  found  with 
it]  will  be  the  "  least"  root :  whence  the  "  greatest"  root  may  be  deduced-.* 
With  these,  the  operation  is  repeated,  setting  aside  the  former  roots  and  ad- 
ditive. This  method  mathematicians  call  that  of  the  circle.  Thus  are  in- 
tegral roots  found  with  four,  two,  or  one  [or  other  number,^  for]  additive : 

'  Chacrac6la,  a  circle;  especially  the  horizon.  The  method  is  so  denominated  because  it  pro- 
ceeds as  in  a  circle:  finding  from  the  roots  ("  greatest"  and  "  least")  a  multiplier  and  a  quotient 
(by  Chapter  2);  and  thence  new  roots;  whence  again  a  multiplier  and  a  quotient,  and  roots  from 
them;  and  so  on  in  a  continued  round.  Sur. 

*  Previously  found  by  §  75.  Crishn. 
'  By  the  method  of  the  pulverizer  (cuttaca).     Ch.  2. 

*  If  the  coefficient  exceed  the  square  of  the  multiplier,  subtract  this  from  the  coefficient;  but, 
if  the  coefficient  be  least,  subtract  it  from  the  square  :  but  so,  as  either  way  the  residue  be  small. 
— Sur.     Else  another  multiplier  is  to  be  sought,  by  Ch.  2. 

'  If  the  square  of  the  multiplier  were  subtracted  from  the  coefficient,  the  sign  of  the  new  addi- 
tive is  reversed  :  if  affirmative,  it  becomes  negative  ;  if  negative,  it  is  changed  to  positive. 

Sur.  and  Crishn. 

*  It  is  deduced  from  the  "  least"  root  and  additive  by  the  conditions  of  the  problem  :  or,  if  re- 
quired, without  the  extraction  of  a  root,  by  this  following  rule.  '  The  original  "  greatest"  root, 
multiplied  by  the  multiplier,  is  added  to  the  "  least"  root  multiplied  by  the  given  coefficient;  and 
the  sum  is  divided  by  the  additive.'  Crishn'. 

^  With  four,  two  or  one,  additive  or  sv.btractive ;  or  w  ith  some  other  number.  Crishn. 


176  VI'JA-GAN'ITA.  Chapter  III. 

and  composition  serves  to  deduce  roots  for  additive  unity,  from  those  which 
answer  to  the  additives  four  and  two  [or  other  numher.]  '■ 

87-  Example :  What  is  the  square,  which,  being  multiplied  by  sixty- 
seven,  and  one  being  added  to  the  product,  will  yield  a  square-root  r  and 
•what  is  that,  which  multiplied  by  sixty-one,  with  unity  added  to  the  pro- 
duct, will  do  so  likewise?  Declare  it,  friend,  if  the  method  of  the  affected 
square  be  thoroughly  spread,  like  a  creeper,*  over  thy  mind. 

Statement  of  Example  1st:  (Putting  unity  for  the  "  least"  root,  and  ne- 
gative three  for  the  additive.)     C  67     L  1     G  8     A3. 

Making  the  "  least"  root  the  dividend,  the  "  greatest"  root  the  additive, 
and  the  additive  the  divisor,  the  statement  for  the  operation  of  fmding  the 

multiplier  (Ch.  2)  is  Dividend  1      Additive  8 
Divisor     3 

Here,  by  the  rule  §  61,  the  series  is  0;  and  the  quotient  and  multiplier 

I 

are  found  0 ;  which,  as  the  number  of  quotients  [in  the  series]  is  uneven, 

2 
must  be  subtracted  from  the  abraders  (§•  57)  leaving  1  ;  and  the  quotient 

1 

obtained  in  the  abrading  of  the  additive  is  to  be  added  (§  61)  to  the  quo- 
tient here  found ;  making  the  quotient  and  multiplier  3     Since  the  divisor 

1 

is  negative,  the  quotient  is  considered  so  too  (§  68)  ;  and  the  quotient  and 

multiplier  are  3     Then  the  square  of  the  multiplier  1,  being  subtracted  from 
1 

the  given  coefficient  67,  leaves  66  ;  which,  however,  is  not  a  small  remainder. 
Putting  therefore  negative  two  for  the  assumed  number  by  §  64,  and  mul- 
tiplying by  that  the  negative  divisor  3,  and  adding  the  product  to  the  mul- 
tiplier, a  new  multiplier  is  found :  viz.  7-     Its  square  49  being  subtracted 

'  If  the  additive  be  already  a  square  integer,  the  problem  of  finding  the  roots  that  answer  to 
additive  unity  is  at  once  solved  by  §  79-  Else  raise  it  to  a  square  by  the  combination  of  like  sets, 
and  then  proceed  by  that  rule.  If  the  roots  so  found  be  not  integral,  repeat  the  method  of  th« 
circle,  until  the  roots  come  out  in  whole  numbers.  Crisiin. 

•  As  a  climbing  plant  spreads  over  a  tree. 


Section  II.  AFFECTED    SQUARE.  177 

from  the  coefficient  67,  the  remainder  1 8,  divided  by  the  original  additive 
3,  yields  6 ;  the  sign  of  which  is  reversed,  as  the  subtraction  was  of  the 
square  of  the  multiplier  from  the  coefficient;  and  it  thus  becomes  6  positive. 
The  quotient  answering  to  the  multiplier,  viz.  5,*  is  the  "  least"  root. 
Whether  this  be  negative  or  affirmative,  makes  no  difference  in  the  further 
operation.  It  is  noted  then  as  5  positive.  Its  square  being  multiplied  by 
the  coefficient,  and  six  being  added  to  the  product,  and  the  square-root 
being  extracted,  the  "  greater"  root  comes  out  4 1 . 

Statement  of  these  again  for  a  further  investigation   of  a  pulverizer: 

Dividends      ajiv      a^ 
T-.-  •  ^     Additive  41. 

Divisor     o 

Here  the  multiplier  is  found,  5.  Its  square,  subtracted  from  the  coeffi- 
cient, leaves  42 ;  which,  divided  by  the  original  additive  6,  yields  7;  the 
sign  whereof  is  reversed  because  the  subtraction  was  from  the  coefficient ; 
and  the  new  additive  comes  out  7.  The  quotient  answering  to  the  multi- 
plier is  the  "  least"  root,  1 1.     Hence  the  "  greatest"  root  is  deduced,  90. 

Statement  of  these  again  for  a  further  pulverizer:  Divd.  11      «  , .  „„ 

Div.       7 

By  the  rule  §  61,  the  abraded  additive  becomes  6,  and  the  multiplier  is 
found  5 ;  and,  since  the  products  in  the  series  are  uneven,  it  is  subtracted 
from  its  abrader,  and  the  multiplier  becomes  2.  Its  negative  divisor  (the 
former  additive)  being  negative  (7)  is  multiplied  by  negative  one  (1)  as- 
sumed by  §  64  and  added  to  that  multiplier,  for  a  new  multipHer  9;  from 
the  square  of  which  81,  subtracting  the  given  coefficient  67,  the  remainder 
14,  divided  by  the  original  additive  7,  gives  the  new  additive  2.  Tlie  quo- 
tient answering  to  the  multiplier  is  the  "  least"  root  27  :  whence  the  "  great- 
est" root  is  found  221.  From  these,  others  are  to  be  deduced  by  combina- 
tion of  like  sets. 

Statement:    L  27     G  221     A  2 
1  27      g  221      a  2 
Proceeding  as   directed,  the  roots  are  found   L  1 1934    G  97684    A  4. 

*  — 3+(lX-2). 
A  A 


178  VI'JA-GAN'ITA.  Chapter  III. 

These  roots  divided  by  the  root  of  the  additive  four,  viz.  2,  give  roots  which 
answer  to  additive  unity  :    L  5967     G  48842     A  1. 

Statement  of  Example  2d.     C  6l     Ll     G8     A3. 

Statement  for  a  pulverizer:    Dividend!      ^^^■^■      o 
'^  T\-  ■  a     Additive  8. 

Divisor      3 

Proceeding  as  before,  by  §61,  and  putting  two  for  the  assumed  number 
(§  64)  the  multipUer  is  found  7.  Whence  roots,  answering  to  the  negative 
additive  four,  are  deduced  L  5  G  39  A  4.  Thence,  by  §  79,  roots  are 
found  for  subtractive  imity,  L  f  G  y  A  i .  Statement  of  these  for  com- 
position L  f  G  V  A  i 
H    g  ¥    a  i. 

From  them  are  deduced  roots  answering  to  additive  unity  L  ^^^  G  i^ 
Al. 

Statement  of  these  again,  with  roots  answering  to  subtractive  unity,  for 
composition  L  -|     G   ^j     A  1 
liM    ^  i^    a  1 

Hence  integral  roots  answering  to  subtractive  unity  are  obtained  L  3805 
G  29718  A  1.  From  these,  by  combining  like  sets,  roots  for  additr\'e 
unity  come  out  (in  whole  numbers)  L  226153980   G  1766319049   A  1. 


(   m  ) 


SECTION  III. 


MISCELLANEOUS   RULES. 

88 — 89/  Rule :-  If  the  multiplier  [that  is,  coefficient  affecting  the 
square]  be  not  the  sum  of  [two]  squares,  when  unity  is  subtractive,  the  in- 
stance proposed  is  imperfect.*  The  instance  being  correctly  put,  let  unity 
twice  set  down  be  divided  by  the  roots  of  the  [component]  squares :  and 
the  quotients  be  taken  as  two  "  least"  roots  answering  to  subtractive  unity  :* 

'  Conclusion  of  a  preceding  stanza  §  86;  one  complete  stanza;  and  beginning  of  another. 

*  Where  unity  is  subtractive,  to  discriminate  impossible  cases;  and  to  solve  the  problem  by 
another  method,  in  those  which  are  possible.  Crishn'. 

'  Undeserving  of  regard.— Sua.  The  square  of  no  number  multiplied  by  such  a  coefficient,  can, 
after  subtraction  of  unity,  be  an  exact  square.  CaiSHV. 

The  subtractive  unity  is  a  square  number.  Now  a  negative  additive  may  be  a  square  number 
if  the  square  of  the  "  least"  root  being  multiplied  by  the  coefficient  comprise  two  squares;  for 
then,  one  square  being  subtracted,  the  other  remains  to  yield  a  square-root.  But,  for  this  end,  it 
is  necessary  that  the  coefficient  should  have  consisted  of  the  sum  of  two  squares  ;  for,  as  a  square 
multiplied  by  a  square  is  a  square,  the  square  of  the  "  least"  root  being  multiplied  by  the  two 
square  component  portions  of  the  coefficient,  the  two  multiples  will  be  squares  and  component 
portions  of  the  product.  Cri'shn. 

In  explanation  of  the  principle  of  this  rule,  Su'ryada'sa  cites  a  maxim,  that  taking  contiguous 
arithmeticals,  or  next  following  terms  in  arithmetical  progression  increasing  by  unity,  twice  the 
sum  of  the  squares  less  one  will  be  a  square  number. 

♦  The  square  of  a  "  least"  root,  [putting  any  number  for  the  root  at  pleasure;]  multiplied  by 
either  component  square  portion  of  the  coefficient,  will  answer  for  a  negative  additive  :  for,  the 
square  of  the  "  least"  root  being  severally  multiplied  by  the  squares  of  which  the  sum  is  the  co- 
efficient, the  two  products  added  together  are  the  square  of  the  "  least"  root  multiplied  by  the 
coefficient;  and,  if  from  that  be  subtracted  the  square  of  the  same  multiplied  by  either  portion  of 
the  coefficient,  the  remainder  will  be  the  square  of  the  same  multiplied  by  the  other  square  por- 
tion of  the  coefficient;  and  of  course  will  yield  a  square-root.  Now  to  deduce  from  this,  roots 
answering  to  subtractive  unity  ;  put  for  the  assumed  number  by  §  79  the  "  least"  root  [any  how 
assumed  as  above]  multiplied  by  the  root  of  either  component  square  portion  of  the  coefficient,  and 

A  .\  2 


180 


VI'JA-G ANITA.  Chapter  III. 


and  the  correspondent  "  greatest"  roots  may  thence  be  deduced.  Or  two 
roots  serving  for  subtractive  unity  may  be  found  in  the  manner  before 
shown. 

90.  Example.  Say  what  square,  being  multiplied  by  thirteen,  with  one 
subtracted  from  the  product,  will  be  a  square  number?  Or  what  square, 
beino-  multiplied  by  eight,  with  one  taken  from  the  product,  will  yield  a 

root  ? 

In  the  first  of  these  instances,  the  coefficient  is  the  sum  of  the  squares  of 
two  and  three.  Therefore  let  unity  divided  by  two  be  a  "  least"  root  for 
subtractive  unity,  -a-.  From  the  square  of  that,  multiplied  by  the  coefficient, 
and  diminished  by  the  subtraction  of  unity,  the  corresponding  "  greatest" 
root  is  deduced,  ^.  Or  let  unity  divided  by  three  be  the  "  least"  root,  -l. 
Hence  the  "  greatest"  root  is  found  -5 .  Or  let  the  "  least"  root  be  1  ;  from 
the  square  of  which,  multiplied  by  the  coefficient,  and  diminished  by  the 
subtraction  of  four,  the  "  greatest"  root  comes  out  3.  Statement  of  them, 
in  their  order,  L  1  G  3  A  4.  By  the  rule  §  79,  roots  answering  to  sub- 
tractive  unity  are  hence  found  ^  f .  Or  subtracting  nine  from  the  square 
of  the  "  least"  root  multiplied  by  the  coefficient,  the  "  greatest"  root  comes 
out:  and  roots  are  thence  found  [by  §  75 — 79]  Li  G^  A  1.  Or  by  the 
cyclic  method  (§  83 — 86)  integral  roots  may  be  deduced.  Thus,  putting 
those  "  least"  and  "greatest"  roots  and  additive  (§83)  for  the  dividend, 
additive  and  divisor,  Dividend  ^   Additive  a-   *"^  reducing  them  by  the 

Divisor  1 
common  measure  half.  Dividend  1  Additive  3  *'^^  multiplier  and  quo- 
Divisor  2 
tient  are  found  by  investigation  of  the  pulverizer  (Ch.  2),  1  and  2.  Here 
putting  negative  unity  for  an  assumed  number,  and  adding  its  multiple  of 
the  divisor  to  the  multiplier,  another  multiplier  is  obtained,  3.  Whence,  by 
the  rule  (§  84),  the  additive  comes  out  4 ;  and  the  quotient  found  with  the 

proceeding  by  tliat  rule,  §79,  the  root  answering  to  subtractive  unity  will  be  the  "  least"  root  [be- 
fore assumed]  divided  by  the  present  assumed  number,  which  is  the  same  "  least"  root  multiplied 
.  by  the  root  of  a  component  portion  of  the  coefficient.  Reduce  the  numerator  and  denominator  of 
this  fractional  value  to  their  least  terms  by  their  common  measure,  the  "  least"  root  [before 
assumed]  ;  the  result  is,  for  numerator,  unity  ;  for  denominator,  the  root  of  the  component  square 
portion  of  the  coefficient.  Crishn. 


Section  III.  AFFECTED    SQUARE.  181 

multiplier,  becomes  the  "  least"  root  3 ;  and  from  these  the  "  greatest"  root 
is  deduced,  11.  Hence  also,  by  repeating  the  cyclic  operation  (§  83 — 84), 
integral  roots  for  subtractive  unity  are  found,  L  5  G  1 8  A  1.  Here,  as 
in  every  instance,  an  infinity  of  roots  may  be  deduced  by  composition  with 
roots  answering  to  unity. 

In  like  manner,  in  the  second  example,  where  the  given  coefficient  is 
eight,  the  "  least"  and  "greatest"  roots,  found  as  above,  are  Li   G  1    A  1.* 

91.  Example:  What  square,  being  multiplied  by  six,  and  having  three 
added  to  it,  will  be  a  square  number?  or  having  twelve  added?  or  with  the 
addition  of  seventy-five  ?  or  with  that  of  three  hundred  ? 

Here,  putting  unity  for  the  "  least"  root,  the  statement  is  C  6  L  1  G  3 
A  3.  Then,  by  rule  §  79,  multiplying  the  roots  by  two,  [and  the  additive 
by  its  square  four,]  the  roots  answering  for  additive  twelve  come  out  L  2 
G  6  A  12.  So,  by  the  same  rule,  multiplying  by  five,  [and  the  additive  by 
twenty-five,]  they  are  found  for  additive  seventy-five,  L5  G  15  A  75. 
Also,  multiplying  by  ten,  [and  the  additive  by  a  hundred,]  they  are  de- 
duced for  additive  three  hundred,    L  10   G  30   A  300. 

92."  Many  being  either  additive  or  subtractive,  corresponding  roots  may 
be  found  [variously]  according  to  the  [operator's]  own  judgment :  and  from 
them  an  infinity  may  be  deduced,  by  composition  with  roots  answering  to 
additive  unity.' 

93.  Rule:*  The  multiplier  [i.e.  coefficient]  being  divided  by  a  square, 
[and  the  roots  answering  to  the  abridged  coefficient  being  thence  found,'] 
divide  the  "  least"  root  by  the  root  of  that  square.* 

*  Roots  in  whole  numbers  may  be  hence  deduced  by  the  cyclic  method,  §  83—86.     Crishn. 

*  Completion  of  one  stanza  §  89  and  half  of  another. 

'  The  preceding  rule  was  unrestrictive.  Finding  by  whatever  means  roots  which  answer  for  the 
proposed  additive,  an  infinity  of  them  is  afterwards  thence  deducible  by  composition  with  additive 
unity  and  its  correspondent  roots  :  as  the  author  here  shows.  Crishji'. 

*  Applicable  when  the  coefficient  is  measured  by  a  square.  Crisiin. 
'  Crisiin. 

'  By  parity,  multiplying  by  any  square  the  given  coefficient,  and  finding  the  "  least"  and 
"  greatest"  roots  for  such  raised  coefficient,  the  "  least"  root  so  found  must  be  multiplied  by  the 
root  of  that  square.  Crishk. 


iSi  VI'JA-GANITA.  Chapter  III. 

Si.  Example :  half  a  stanza.  Say  what  square  being  multipUed  by 
thirty-two,  with  one  added  to  tlie  product,  will  yield  a  square-root  ? 

Statement :  C  32.  The  "  least"  and  "  greatest"  roots,  found  as  before, 
are  L  J-  G  3  A  1.  Or,  by  the  present  rule  ^93,  the  coefficient  32  divided 
by  four,  gives  8;  to  which  the  roots  corresponding  are  found  L  1  G  3  A  1 ; 
and  dividing  the  "least"  root  by  the  root  (2)  of  the  square  (4-)  by  which  the 
coefficient  was  divided,  the  two  toots  for  the  coefficient  thirty-two,  come 
out  Ll  G3   A  1. 

Or,  dividing  the  coefficient  by  sixteen,  it  gives  2 ;  to  which  the  roots 
corresponding  are  L  2  G  3  A  1 ;  whence,  dividing  the  "  least"  root  by  the 
square-root  (4)  of  the  divisor  (16),  the  roots  answering  to  the  entire  coeffi- 
cient are  deduced  La   G  3  A  1 . 

Or,  by  the  investigation  of  a  pulverizer  (Ch.  2)  integral  roots  are  obtained 
(§  83—86).     L3   G  17   A  1. 

95.  Rule  :*  The  additive,"  divided  by  an  assumed  quantity,  is  twice  set 
down,  and  the  assumed  quantity  is  subtracted  in  one  instance,  and  added 
in  the  other  :  each  is  halved ;  and  the  first  is  divided  by  the  square-root  of 
the   multiplier   [that   is,    coefficient.]      The   results   are   the   "least"  and 


"  greatest"  roots  in  their  order.^ 


'  Applicable  when  the  coefficient  is  a  square  number.  Ciushn. 

*  The  rule  holds  equally  for  a  subtractive  quantity  :  but  with  this  difference,  that  the  subtrac- 
tion and  addition  of  the  number  put  are  transposed  to  yield  the  "  least"  and  "  greatest"  roots  in 
their  order.  Or  the  rule  may  be  applied  as  it  stands,  observing  to  give  the  negative  sign  to  the 
additive :  but  the  "  least"  and  "  greatest"  roots  will  in  this  manner  come  out  negative.  It  is,  there- 
fore, preferable  to  transpose  the  operations  of  subtraction  and  addition  of  the  assumed  number. 

Crishv. 

'  The  square  of  the  "  least"  root  being  multiplied  by  a  coefficient  which  also  is  a  square,  the 
product  will  be  a  square  number.  The  additive  being  added,  if  the  sum  too  be  a  square,  [square 
of  the  "  greatest"  root ;]  the  additive  must  be  the  difference  of  the  squares.  Now  the  difference 
of  two  squares,  divided  by  the  difference  of  the  two  simple  quantities,  will  be  their  sura.  Hence, 
putting  any  assumed  number  for  the  difference,  and  dividing  by  it  the  additive  equal  to  the  differ- 
ence of  the  squares,  the  quotient  is  the  sum  of  the  two  quantities.  Then,  by  the  rule  of  concur- 
rence (Li/.  §  55),  the  finding  of  the  two  quantities  is  easy.  The  one  is  the  "  greatest"  root ;  the 
other  is  the  "  least"  root  taken  into  the  root  of  the  coefficient.  Therefore,  by  inversion,  that 
quantity,  divided  by  the  root  of  the  coefficient,  will  be  the  "  least"  root.       Sua,  and  Chishn. 


Section  III.  AFFECTED    SQUARE.  183 

96.  Example:  What  square,  being  multiplied  by  nine,  and  having 
fifty-two  added  to  the  product,  will  be  square?  or  what  square  number,  being 
multiplied  by  four,  and  having  thirty-three  added,  will  be  square? 

Here,  in  the  first  example,  the  additive  fifty-two  being  divided  by  an 
assumed  number  two,  and  the  quotient  set  down  twice,  diminished  and  in- 
creased by  the  assumed  number  and  then  halved,  gives  12  and  14.  The  first 
of  these  is  divided  by  the  square-root  of  the  given  coefficient;  and  the 
"least"  and  "greatest"  roots  are  found,  L  4   G  14. 

Or  dividing  the  additive  32  by  four,  they  thus  come  out  L|^    G  t/- 

In  the  second  example,  dividing  the  additive  thirty-three  by  one  put  for 
the  assumed  number,  the  "least"  and  " greatest"  roots  are  in  like  manner 
deduced,  L8    G  17.     Or,  putting  three,  they  are  L  2    G  7- ^ 

97-  Example  :*  Declare  what  square  multiplied  by  thirteen,  and  lessened 
by  subtraction  of  thirteen,  or  increased  by  addition  of  the  same  number, 
will  be  a  square  ? 

In  the  first  example,  coefficient  13.  The  "least"  and  "greatest"  roots 
found  [for  the  subtractive  quantity]  are  L  1  GO.  Put  an  assumed  number 
3;  and,  by  rule  §  80 — 81,  roots  answering  for  additive  unity  are  found  L-f- 
G  y.  From  these,  by  composition,  roots  answering  to  the  negative  addi- 
tive thirteen  are  deduced  L  y  G  *^.  From  which  roots,  corresponding 
to  the  negative  additive,  together  with  these  other  roots  L  ^  G  -|  answer- 
ing to  subtractive  unity,  by  the  method  of  composition  by  difference,  roots 
suited  to  additive  thirteen  are  obtained  L  f  G  y.  Or  by  composition  by 
sum,  they  come  out  L  1 8    G  65. 

98.  Example:*  Say  what  square,  multiplied  by  negative  five,  with 
twenty-one  added  to  the  product,  will  be  a  square  number  ?  if  thou  know 
the  method  for  a  negative  coefficient. 

Statement:     C  5     A  21. 

Here,  putting  one,  the  roots  are  1  and  4.     Or  putting  two,  they  are  2  and  I . 

'  Thus,  by  varying  the  assumptions,  an  infinity  of  results  may  be  obtained.  Cri'siin. 

■*  To  elucidate  the  case  when  the  additive  equals  the  coefficient.  Crishn. 

'  Showing,  that  roots  may  be  found,  even  in  cases  where  the  coefficient  is  negative.    CafsHN. 


184  VI'JA-GAN'ITA.  Chapter  III. 

By  composition  with  roots  adapted  to  negative  unity,    an  infinity   may 
be  deduced. 

99.  This  computation,  truly  applicable  to  algebraic  investigation,  has 
been  briefly  set  forth.  Next  I  will  propound  algebrq,  affording  gratification 
to  mathematicians.* 

'  By  tbis  conclusion  k  is  intimated,  that  the  contents  of  the  preceding  chapters  (1 — 3)  are  in- 
troductory to  the  analysis,  which  the  author  proposed  as  the  subject  in  the  opening  of  the  treatise 
(^  2);  and  to  which  he  now  proceeds  in  the  next  chapters  (4 — 8).     See  Su'r.  and  CRfsuN. 


CHAPTER   IV. 


SIMPLE    EQUATIONS 

100 — 102.  Rule:  Let  "so  much  as"  (yavat-tctcat}*  be  put  for  the 
value  of  the  unknown  quantity ;'  and  doing  with  that  precisely  what  is  pro- 
posed in  the  instance,  let  two  equal  sides  be  carefully  completed,  adding 
or  subtracting,  multiplying  or  dividing,*  [as  the  case  may  require.] 

101.  Subtract  the  unknown  quantity  of  one  side  from  that  of  the  other; 
and  the  known  number  of  the  one  from  that  of  the  other  side.  Then  by  the 
remaining  unknown  divide  the  remainder  of  the  known  quantity  :  the  quo- 
tient is  the  distinct  value  of  the  unknown  quantity.' 

'  Eca-varna-samicarana,  equation  uniliteral  or  involving  a  single  unknown  quantity.  See 
note  2  in  next  pagel 

*  See§  17. 

'  Avyada-r&si,  indistinct  quantity  or  unknown  number  (ajny&tanca)  ;  the  unknown  is  repre- 
sented by  ydvat-tdvaf ;  or,  if  there  be  more  than  one,  by  colours  or  letters  (§  17)  ;  the  known,  by 
rupa,  form,  species,  (absolute  number.)     See  Sua. 

*  Or  by  multiplying  and  adding;  or  by  multiplying  and  subtracting;  by  dividing  and  adding; 
or  by  dividing  and  subtracting ;  or  by  raising  to  a  square  or  other  [power].  Crishn. 

This  first  rule  is  common  to  all  algebraic  analysis.  lb. 

'  Whatever  be  the  unknown  quantity  (whether  unit  or  aggregate  of  the  known,  or  a  part  or 
fraction  of  such  unit  or  aggregate,)  is  yet  not  specifically  known.  It  is  therefore  denominated  in- 
distinct or  unknown ;  while  that,  which  is  specifically  known,  is  termed  distinct  or  known  species. 
The  operations  indicated  by  the  enunciation  of  the  example  being  performed  with  the  designation 
of  the  unknown,  if  by  any  means,  conforniably  with  the  tenor  of  the  instance,  there  at  once  be 
equality  of  the  two  sides,  a  value  of  the  unknown  in  the  known  species  is  easily  deducible.  Thus, 
if  on  one  side,  there  be  only  known  number,  and  on  the  other  side  the  unknown  quantity  only, 
then,  as  being  equal,  those  numbers  are  a  true  value  in  the  known,  of  that  amount  of  the  un- 
known.   Hence,  by  rule  of  three,  the  quantity  sought  is  found :    viz.   '  of  so  many  unknown 

B  B 


18(J  VI'JA-GAN'ITA.  Chapter  IV. 

102.  Under  this  head,  for  two  or  more  unknown  quantities  also,  [the  al- 
gebraist] may  put,  according  to  his  own  judgment,  multiples  or  fractions  of 
"so  much  as,"  (that  is,  yavat-tavat,  multiplied  by  two,  &c.  or  divided  ;)  or 
the  same  with  addition  or  deduction  [of  known  quantities.]  Or  in  some 
cases  he  may  assume  a  known  value  ;  with  due  attention  likewise  [to  the 
problem.] 

V  The  first  analysis  is  an  equation  involving  a  single  colour  (or  letter).* 
The  second  mode  of  analysis  is  an  etjuation  involving  more  than  one  colour 
(or  letter).*     Where  the  equation  comprises  one,  two  or  more  colours,  raised 

(y&vat-tavat)  if  so  many  known  (rupa)  be  the  value,  then  of  the  proposed  number  of  unknown, 
what  is  the  value  ?'  But,  shoultl  there  be  on  both  sides  some  terms  of  each  sort,,  it  must  be  so 
managed,  that  on  one  side  there  be  only  terms  of  the  unknown  ;  and  on  the  other,  of  the  known. 
Now  it  is  a  maxim,  that,  if  equal  [things]  be  added  to,  or  subtracted  from,  or  multiply,  or  divide, 
equal  [things],  the  equality  is  not  destroyed :  as  is  clear.  If  then,  from  one  side,  the  terms  of 
the  unknown  contained  in  it  be  subtracted,  there  remain  only  known  numbers  on  that  side :  but, 
for  equality's  sake,  the  like  amount  of  unknown  must  be  subtracted  from  the  other  side.  The  same 
is  to  be  done  in  regard  to  the  known  number  on  one  side,  which  must  be  subtracted  also  from  the 
other.  This  being  effected,  there  remain  only  terms  of  the  unknown  on  one  side ;  and  of  the 
known  on  the  other.  Then,  by  rule  of  three,  '  if  by  this  unknown  quantity  this  known  number 
be  had,  then  by  the  stated  amount  of  the  unknown  what  is  obtained?'  the  remaining  known  term 
is  to  be  divided  by  the  residue  of  the  unknown  and  to  be  multiplied  by  the  proposed  unknown. 
The  one  operation  (that  of  division)  is  directed  by  the  rule  (§  101);  the  other  (the  multiplication) 
is  comprehended  in  (utt'hupaaa)  the  "  raising"  of  the  answer;*  both  being  reduced  to  proportions 
in  which  one  term  is  unity.  Therefore,  by  any  means,  (by  subtraction  or  some  other,)  the  twa 
sides  of  the  equation  are  to  be  so  treated,  consistently,  however,  with  their  equality,  as  that 
known  number  may  be  on  one  side,  and  unknown  quantity  on  the  other.  Else  the  solution  will 
not  be  easy.  Crishn, 

'  Or  symbol  of  unknown  quantity. 

*  Sam'icarana,  sam'icdra,  samicriya,  equation  :  from  sama,  equal,  and  cri,  to  do  :  a  making  equal. 
It  consists  of  two  sides  (pacsha)  ;  and  each  may  comprise  several  terms  (c'handa,  lit.  part). 

The  primary  distinction  of  analysis  (V'tja)  is  twofold  ;  1st.  uniliteral  or  equation  involving  one 
unknown,  eca-varna-samicarana ;  where,  a  single  unknown  quantity  designated  by  letter  or  colour 
(§  17)  being  premised,  two  sides  are  equated  ;  2d.  multiliteral  or  equation  involving  several  un- 
known, aneca-vania-samicararia,  where,  more  than  one  unknown  quantity  represented  severally  by 
colours  or  letters  being  premised,  two  sides  are  equated.  The  first  comprises  two,  and  the  second 
three  sorts:  viz.  1st.  equation  involving  a  single  and  simple  unknown  quantity  ;  2d.  equation  in- 
volving a  single  unknown  raised  to  a  square  or  higher  power;  3d.  equation  involving  several  simple 
unknown  quantities  ;   4th.  equation  involving  several  unknown  raised  to  the  square  or  higher 

power;  5th.  equation  involving  products  of  two  or  more  unknown  quantities  multiplied  together. 
-■ij 

*  Deducing  of  the  answer  by  subsUtution  oi  value.     See  note  1,  p.  188.  and  glow  on  $  lo3 — 156. 


SIMPLE    EQUATION.  187 

to  the  square  or  other  [power,]  it  is  termed  (mad'hyamaharana)  elimination 
of  the  middle  term.  Where  it  comprises  a  (bhdvita)  product,  it  is  called, 
(bharita)  involving  product  of  unknown  quantities.  Thus  teachers  of  the 
science  pronounce  analysis  fourfold. 

The  first  of  these  is  so  fer  explained :  an  example  being  proposed  by  the 
questioner,  the  value  of  the  unknown  quantity  should  be  put  once,  twice, 
or  other  multiple  of  "  so  much  as"  (ydvat-tavat)  :  and  on  that  unknown 
quantity  so  designated,  every  operation,  as  implied  by  the  tenor  of  the  in- 
stance,^ whether  multiplication,  division,  rule  of  three,  [summing  of]  pro- 
gression, or  [measure  of]  plane  figure,  is  to  be  performed  by  the  calculator. 
Having  so  done,  he  is  diligently  to  make  the  two  sides  equal.  If  they  be 
not  so  in  the  simple  enunciation  [of  the  problem] ;  they  must  be  rendered 
equal  by  adding  something  to  either  side,  or  subtracting  from  it,  or  multi- 
plying by  some  quantity  or  dividing.-  Then  the  unknown  quantity  of  one 
of  the  two  sides  is  to  be  subtracted  from  the  unknown  of  the  other  side ;  and, 
in  hke  manner,  the  square  or  other  [power]  of  the  unknown.  The  known 
numbers  of  one  side  are  to  be  likewise  subtracted  from  the  known  numbers 
of  the  other.'  If  there  be  surds,  they  too  must  be  subtracted  by  the  method 
before  taught.*     Then,  by  the  residue  of  the  unknown  quantity,  dividing 

These  distinctions  are  reducible  to  four,  by  uniting  the  quadratics  or  equations  of  higher  degree 
under  one  head  of  analysis ;  where,  a  power  (square  or  other)  of  an  uniinown  quantity  represented 
by  colour  or  letter  (or  more  than  one  such)  being  premised,  and  sides  being  equated,  the  value  is 
found  by  means  of  extraction  of  the  root.  It  is  called  mod^hi/amd'harana;  and  is  so  denominated 
because  the  middle  term  (mad'hyama  c'handa)  is  generally  removed :  being  derived  from  mad'hyama, 
middlemost,  and  aharana,  removal  or  elimination.  (See  Chap.  5.)  These  four  distinctions  are 
received  by  former  writers  :•  the  author  himself,  however,  intimates  his  own  preference  of  the 
primary  distinction  alone.  Crishit. 

*  AMpa,  enunciation  of  the  pr'tch'haca,  or  of  the  person  proposing  the  question ;  or  tenor  of  the 
instance  (uddesaca)  ;  the  condition  of  the  problem. 

*  By  superadding  something  to  the  least  side  ;  or  subtracting  it  from  the  greater ;  or  multiplying 
by  it  the  less  side  ;  or  dividing  by  it  the  greater.  Ckishn. 

'  The  side  containing  the  lowest  unknown  has  the  most  known ;  and  conversely.  Ordering  the 
work  accordingly,  subtract  the  unknown  in  the  second  from  that  in  the  first  side ;  and  the  known 
in  the  first  from  that  in  the  second.— Sub.  If  there  be  a  square  or  other  {power]  of  the  unknown, 
that  also  is  to  be  subtracted  from  the  like  term  of  the  other  side,  CaiSHN. 

*  Ch.  1.  Sect.  4.  Though  the  unknown  or  its  power  have  a  surd  multiplier,  subtraction  must 
take  place.    The  residue  having  still  a  surd  coefficient,  divide  by  that  surd  the  remainder  of  known 

•  S«e  CiiATjjBviDA  on  Braiimeodfta,  (Brofcm.  12,  ^66  and  18,  $  38). 
BB  2 


[ 


W8  VIJA-GANITA.  Chapter  IV. 

the  remainder  of  the  known  numbers,  the  quotient  thus  obtained  becomes 
the  value  known  of  one  unknown  :  and  thence  the  proposed  unknown  quan- 
tity instanced  is  to  be  "  raised."  *  If  in  the  example  there  be  two  or  more 
unknown  quantities  comprised,"  putting  for  one  of  them  one  "  so  much  as", 
let  "  so  much  as"  (ydvat-t&vat)  multiplied  by  two  or  another  assumetl  num- 
ber, or  divided  by  it,  or  lessened  by  some  assumed  number,  or  increased  by 
it,  be  put  for  the  rest.  Or  let  "  so  much  as"  (ydxat-tdvat)  be  put  for  one ; 
and  known  values  for  the  others.  With  due  attention :  that  is,  the  intelli- 
gent calculator,  considering  how  the  task  may  be  best  accomplished,  should 
so  put  known  or  unknown  values  of  the  rest.     Such  is  the  meaning. 

103 — 104.  Examples  :  One  person  has  three  hundred  of  known  species 
and  six  horses.  Another  has  ten  horses  of  like  price,  but  he  owes  a  debt  of 
one  hundred  of  known  species.  They  are  both  equally  rich.  What  is  the 
price  of  a  horse  r  * 

104.  If  half  the  wealth  of  the  first,  with  two  added,  be  equal  to  the 
wealth  of  the  second;  or  if  the  first  be  three  times  as  rich  as  the  other,  tell 
me  in  the  several  cases  the  value  of  a  horse.* 

number  whether  rational  or  irrational ;  that  is,  "  square  by  square"  (§29);  and  extract  the  square- 
root  of  the  quotient;  which  will  be  the  value  of  the  uniinown;  or,  if  the  quotient  be  irrational, 
note  it  as  a  surd  value.  So,  in  deducing  an  answer  from  that  surd  value,  "  multiply  square  by 
square"  (§  29)  and  extract  the  root,  or  note  the  surd.  Cri'shi/. 

'  The  value  of  the  unknown  being  thus  found  in  an  expression  of  the  known ;  the  answer  of  the 
question,  or  quantity  sought,  is  deducibJe  from  it  by  the  rule  of  proportion  ;  and  the  first  term  of 
the  proportion  being  unity,  the  operation  is  a  simple  multiplication.  This  finding  of  the  quantity 
sought,  or  answer  to  the  question,  being  the  stated  unknown  quantity  in  the  instance,  is  termed 
utt'hdpana  ,  a  "  raising"  of  it,  or  substitution  of  a  value.  See  Ckishn'a;  and  the  author's  gloss  on 
the  first  rule  of  Chapter  6. 

*  Although  such  examples  come  of  course  under  equations  involving  more  than  one  unknown, 
the  author  has  introduced  the  subject  for  gratification  and  exercise  of  the  understanding. 
— Cri'shn.     See  Ch.  5. 

Reserving  one  among  two  or  more  unknown  quantities,  if  values  of  the  rest,  in  expressions  of 
that  or  of  the  known  species,  be  assumed  either  equal  or  unequal  or  at  pleasure,  then,  from  the 
value  of  the  unknown  thence  found,  a  true  answer  for  the  instance  will  be  deducible.     Crishx. 

'  This  is  an  example  of  an  equation  according  to  the  simple  enunciation  of  the  instance. 

Crishn. 

♦  Instances  of  adding  or  subtracting,  multiplying  or  dividing,  (§  lOO)  to  produce  the  equation. 

Crisun. 


SIMPLE    EQUATION.  I89 

Example  1st:  Here  the  price  of  a  horse  is  unknown.  Its  value  is  put 
one  "  so  much  as"  (ydvat-tavat)  ya  1  ;  and  by  rule  of  three,  '  if  the  price  of 
one  horse  be  ydvat-tdvat,  what  is  the  price  of  six  ?'  Statement :  1  |  ^^a  1  | 
6  \  .  The  fruit,  multiplied  by  the  demand,  and  divided  by  the  argu- 
ment,^ gives  the  price  of  six  horses,  ya  6.  Three  hundred  of  known  species 
being  superadded,  the  wealth  of  the  first  person  results ;  ya  6  ru  300.  In 
like  manner  the  price  of  ten  horses  is  ya  10.  To  this  being  superadded  a 
hundred  of  known  species  made  negative,  the  wealth  of  the  second  person 
results;  ya  10  ru  100.  These  two  persons  are  equally  rich.  The  two  sides, 
therefore,  are  of  themselves  become  equal.  Statement  of  them  for  equal 
subtraction  3^fl    6  ru  300     Then,  by  the  rule  (§  101),  the  unknown  of  the 

ya  10  ru  100 
first  side  being  subtracted  from  the  unknown  of  the  other,  the  residue  is 
ya  4.  And  the  known  numbers  of  the  second  side  being  subtracted  from 
the  known  numbers  of  the  first,  the  remainder  is  400.  The  remainder  of 
known  number  400,  being  divided  by  the  residue  of  unknown  ya  4,  the 
quotient  is  the  value  in  known  species,  of  one  "  so  much  as"  (ydvat-tdvat) 
viz.  100.  'If,  of  one  horse,  this  be  the  value,  then  of  six  what?'  By  this 
proportion  the  price  of  six  horses  is  found,  600 ;  to  which  three  hundred  of 
known  species  being  added,  the  wealth  of  the  first  person  is  found,  900.  In 
like  manner,  that  of  the  second  also  comes  out  900. 

Example  2d :  The  funds  of  the  first  and  second  persons  are,  as  before, 
these :    ya    6  ru  300 

ya  10  ru  100  '  - 

Here  the  wealth  of  the  one  is  equal  to  half  that  of  the  other  with  two 
added ;  as  is  specified  in  the  example.  Hence,  the  capital  of  the  first  being 
halved  and  two  added  to  the  moiety  ;  or  that  of  the  second  less  two  being 
doubled ;  the  two  sides  become  equal.  That  being  done,  the  statement  for 
subtraction  is  ya    3  ru  152  or  ya   6  ru  300      From  both  of  which,  sub- 

ya  \0  ru  100       ya^O  ru  204 
traction,  &c.  being  made,  the  value  of  one  "  so  much  as"   (ydvat-tdvat)  is 
found  36.     Whence,  "  raising"  as  before,  the  capitals  of  the  two  come  out 
516  and  260. 

•  Ulaxati,  §  70. 


igo  VI'JA-GAN'ITA.  ChapterIV. 

Example   3d :      The   capitals   are  expressed   by   the    same   terms,    viz. 
ya   6    ru  300 
7/a  10    ru  100 

The  third  part  of  the  first  person's  wealth  is  equal  to  the  second's ;  or 
three  times  the  last  equals  the  first.    Statement:  j/a   6  ru  300  ov  ya   2  rw  100 

ya  30  ru  300  ya  10  ru  100 
By  the  equation  the  value  of  "so  much  as"  (ydvai-tdvat)  is  found  25. 
From  which  "  raising"  the  answers,  the  capitals  come  out  450  and  150. 

105.  Example:'  The  quantity  of  rubies  without  flaw,  sapphires,  and 
pearls  belonging  to  one  person,  is  five,  eight  and  seven  respectively ;  the 
number  of  like  gems  appertaining  to  another  is  seven,  nine  and  six  :  one 
has  ninety,  the  other  sixty-two,  known  species.  They  are  equally  rich. 
Tell  me  quickly  then,  intelligent  friend,  who  art  conversant  with  algebra, 
the  prices  of  each  sort  of  gem. 

Here  the  unknown  quantities  being  numerous,  the  [relative]  values  of  the 
rubies  and  the  rest  are  put  yaS  ya2  yal.  '  If  of  one  gem  this  be  the  price, 
then  of  the  proposed  gems  what  is  the  price  ?'  The  number  of  (ydvat-tdvat) 
the  unknown,  found  by  this  proportion,  being  summed,  and  ninety  being 
added,  the  property  of  the  first  person  is  j/fl  38  ru90.  In  like  manner  the 
second  person's  capital  is  ya  45  ru  62.  They  are  equally  rich.  Statement 
•of  the  two  for  equal  subtraction  ya3%   ru  90    Equal  subtraction  being  made, 

ya  45  ru  62 
the  value  of  the  unknown  is  found  4.  "  Raising"  from  it  by  the  proportion 
'  M  o^  one  ydvat-tdvat  this  be  the  value,  then  of  three  (or  of  two)  what?* 
the  prices  of  a  ruby  and  the  rest  are  deduced  :  viz.  12,  8,  4.  '  If  of  one 
ruby  this  be  the  price,  then  of  five  what?'  the  amount  of  rubies  comes  out 
60.  In  like  manner  sapphires  64 ;  pearls  7-  Total  of  these,  with  the  addi- 
tion of  the  absolute  number  90,  gives  the  whole  capital  of  the  one,  242: 
and,  in  like  manner,  that  of  the  other,  242. 

Or  let  the  value  of  a  ruby  be  put  ya  1  ;  and  the  prices  of  sapphires  and 
pearls  be  p.ut  in  known  species,  5  and  3.  '  If  of  one  ydvat-tdvat  this  be  the 
pjice,  then  of  five  what?'  Thus  the  price  of  five  rubies  is  found  ya  5  ;  and 
the  amount  of  sapphires  and  pearls,  40  and  2 1 .     The  sum  of  the  two,  with 

'  An  instance  of  more  than  one  unknown  quantity,  and  of  putting  assumed  values  (§  102). 

Chisiin. 


SIMPLE    EQUATION.  191 

ninety  added,  is  ru  151:     In  like  manner  the  capital  of  the  second  person  is 
yal    ru  125.     Statement  for  equal  subtraction  ya  5   ra  151     Subtraction 

ya  7  ru  YIS 
being  made,   tlie  value  of  yavat-tavat  comes  out  13.     Hence  by  "raising" 
the  answers,  the  equal  amount  of  capital  is  deduced,  216.' 

In  like  manner,  by  virtue  of  [a  variety  of]  assumptions,  a  multiplicity  of 
answers  may  be  obtained. 

106.  Example  :'  One  says  "  give  me  a  hundred,  and  I  shall  be  twice  as 
rich  as  you,  friend  !"  The  other  replies,  "  if  you  deliver  ten  to  me,  I  shall 
be  six  times  as  rich  as  you."  Tell  me  what  was  the  amount  of  their  re- 
spective capitals  ?  J 

Here,  putting  the  capital  of  the  first  ya  2   ru  100,  and  that  of  the  second; 

ya  1    ru  100  ;  the  first  of  these,  taking  a  hundred  from  the  other,  is  twice  as 

rich  as  he  is :  and  thus  one  of  tlie  conditions  is  fulfilled.     But  taking  ten 

from  the  first,  the  capital  of  the  last  with  the  addition  of  ten  is  six  times  as 

great  as  that  of  the  first :  therefore  multiplying  the  first  by  six,  the  statement 

\?,ya  12    ru  660     Hence  by  the  equation,  the  value  of  "  so  much  as"  (ydvat- 
ya    1    ru  1 10 

tdvat)   is  found,  70.     Thence,  by  "  raising"  the  answer,  the  original  capi- 
tals are  deduced  40  and  170.' 

107.  Example  :*  Eight  rubies,  ten  emeralds  and  a  hundred  pearls,  which 
are  in  thy  ear-ring,  my  beloved,  were  purchased  by  me  for  thee,  at  an  equal 
amount ;  and  the  sum  of  the  rates  of  the  three  sorts  of  gems  was  three  less 
than  half  a  hundred :  tell  me  the  rate  of  each,  if  thou  be  skilled,  auspicious 
woman,  in  this  computation. 

Here  put  the  equal  amount  ya  1.  Then  by  the  rule  of  three  'If  this  be 
the  price  of  eight  rubies,  what  is  the  price  of  one  ?'  and,  in  like  manner,  [for 
the  rest,]  the  rates  in  the  several  instances  are  ya  \,  ya  -^,  ya  -j-^-o .  The  sum 
of  these  is  equal  to  forty-seven. 

■  See  the  solution  conducted  with  more  than  one  symbol  of  unknown  quantity.     Ch.  6. 

*  Instance  of  putting  multiples  of  the  unlinown  with  addition  or  subtraction  of  known  quanti- 
ties (§  132). — Cri'siin.     The  question,  however,  requires  no  arbitrary  assumption. 

^  See  the  solution  otherwise  managed  in  Ch.  6. 

*  This  and  the  following  examples  are  introduced  for  the  gratification  of  learners.       CRfsHN.-  ■ 


P 


192  VI'JA-GAN'ITA.  Chapter  IV. 

Statement  for  like  subtraction  ya  ^Vt  ^"    ^     Reducing  the  two  sides  of 

ya  0  ru  47 
the  equation  to  a  common  denomination  and  dropping  the  denominator,  the 
equation  gives  the  value  of  the  unknown  (ydvat-tavat)  200.  Hence', 
"  raising"  the  answer,  the  rates  of  the  gems  are  found,  rubies  at  25  ;  eme- 
ralds at  20 ;  pearls  at  2.  The  ccjual  amount  of  purchase  of  each  sort  is  200. 
The  cost  of  the  gems  in  the  ear-ring  600. 

Here,  having  reduced  the  terms  to  a  common  denomination,  and  proceed- 
ing to  subtraction,  when  the  first  side  of  the  equation  is  to  be  divided  by  the 
other,  the  numerator  and  denominator  being  transposed,  the  denominator  is 
both  multiplier  and  divisor  of  the  second  side  of  the  equation.  Being  equal 
they  destroy  each  other.  Therefore,  disappearance  of  the  denominator ' 
takes  place. 

108.  Example:^  Out  of  a  swarm  of  bees,  one  fifth  settled  on  a  blossom 
of  nauclea  (cadamba)  ;  and  one  third,  on  a  flower  of  sil'mdhri ;  three 
times  the  difference  of  those  numbers  flew  to  the  bloom  of  an  echites  (cu- 
^aja).  One  bee,  which  remained,  hovered  and  flew  about  in  the  air,  allured 
at  the  same  moment  by  the  pleasing  fragrance  of  a  jasmin  and  pandanus. 
Tell  me,  charming  woman,  the  number  of  bees. 

Here  the  number  of  the  swann  of  bees  is  put  ya  1.  Hence  the  number 
of  bees  gone  to  the  blossom  of  the  nauclea  and  the  rest  of  the  flowers  men- 
tioned, is  j/fl  \^.     This,  with  the  one  specified  bee,  is  equal  to  the  proposed 

unknown  quantity  (ydvat-tdvat).     The  statement  therefore  is  ya\^  ^"rf 
!  :  ya  I     ru  0 

Reducing  these  to  a  common  denomination  and  dropping  the  denominator, 
the  value  of  the  unknown  (ydvat-tdvat)  is  found,  as  before,  15.  This  is 
the  mmibcr  of  the  swarm  of  bees. 

'  Ch'heda-gama ;  departure,  or  disappearance,  of  the  denominator.  Equal  subtraction  being 
made,  when,  conformably  with  the  order  of  proceeding  (§  101),  the  remainder  of  known  number 
is  divided  by  the  residue  of  unknown  quantity,  the  transposition  of  numerator  and  denominator 
takes  place  by  the  rule  of  division  of  fractions,  (Lil.  §  40  J  Thus  the  remainder  of  known  num- 
ber is  multiplied  by  the  denominator  of  the  unknown  in  one  operation,  and  divided  by  it  in  the 
other.  Wherefore,  the  multiplier  and  divisor,  as  being  equal,  are  both  destroyed.  Thus  depar- 
ture of  the  denominator  takes  place.  Su'r. 

*  This  example  occurs  also  in  the  author's  treatise  of  Arithmetic.    See  LU.  §  54. 


SIMPLE    EQUATION.  193 

109.  Example;  here  adduced  for  an  easy  solution,  though  exhibited  by 
another  author  ■}  Subtracting  from  a  sum  lent  at  five  in  the  hundred,  the 
square  of  the  interest,  the  remainder  was  lent  at  ten  in  the  hundred.  The 
time  of  both  loans  was  alike,  and  the  amount  of  the  interest  equal.  [Say 
what  were  the  principal  sums  ?]" 

Here,  if  the  period  be  put  ydvat-tdvat,    the  task  is  not  accomplished. 

Therefore  the  time  is  assumed  five  months ;  and  the  principal  sum  is  put 

ydvat-tavat  I.     With  this,  the  statement  for  rule  of  five'  is       1         5     The 

100   ya  1 
5 

interest  comes  out  ya  \.  Its  square,  ya  v  -^,  being  subtracted  from  the 
principal  sum  after  reducing  to  a  common  denominator,  the  second  principal 
sum  is  found  ya  v  ^  ya  \^.  Here  also,  for  [the  interest  for]  five  months, 
by  the  rule  of  five,  the  statement  is       1  5  Answer :  the  interest 

100  yav^'^   ^fl|| 
10 
is  ya  V  -jV   ya  a-|-     This  is  equal  to  the  interest  before  found,  namely  ya  ^. 
Reducing  the  two  sides  of  the  equation  to  their  least  terms  by  their  com- 
mon measure  ydvat-tcvcat,  the  statement  of  them  for  equal  subtraction  is 
ya  0      ru  \     Proceeding  as  before,*  the  value  of  the  unknown  ydvat-idvat 
ya^  ruW 
is  found  8.     It  is  the  principal  sum. 

Or  else  [it  may  be  solved  in  this  following  manner.^]  The  rate  of  in- 
terest for  the  second  loan  being  divided  by  the  rate  of  interest  for  the  first, 
the  quotient  is  a  multiplier,  by  which  the  second  principal  sum  being  mul- 
tiplied will  be  equal  to  the  first.  For,  else,  how  should  the  interest  in  equal 
times  be  equal  r  The  multiplier  of  the  second  sum  is,  therefore,  in  the  pre- 
sent instance  2.  The  second  sum,  multiplied  by  one,  and  taken  into  the 
multiplier  less  one,  is  equal  to  the  square  of  the  interest.     Hence  the  square 

'  It  has  been  inserted  by  certain  earlier  writers  in  their  treatises ;  and  is  introduced  by  the 
author  for  a  display  of  his  skill  in  the  solution  of  the  problem.  It  is  a  mixt  one,  and  solved  [as  an 
indeterminate]  by  an  equation  involving  one  unknown. — SuR.  It  is  cited  for  the  purpose  of  ex- 
hibiting an  easy  solution.  Crishn. 

*  Crishn. 

'  To  find  the  interest.— Cri'shn.     See  L'd.  §  79. 

♦  That  is,  reducing  to  a  common  denominatiun  and  dropping  the  denominator.  Cri'shi/. 
'  Without  putting  an  algebraic  symbol  for  the  unknown  quantity.  CRiSHif . 

C  C 


J94  VI'JA-GAN'ITA.  Chapter  IV. 

of  an  assumed  amount  of  interest,  being  divided  by  the  multiplier  less  one, 
the  quotient  will  be  the  second  principal  sum  :  and  this,  added  to  the  square 
of  the  interest,  will  be  the  first  sum.'  Let  the  square  of  the  interest  then 
be  put  4.  Hence  the  first  and  second  sums  are  found  8  and  4,  and  the  in- 
terest 2.  '  If  the  interest  of  a  hundred  be  five,  then  of  eight  what  ?'  By 
this  proportion  the  interest  of  eight  for  one  month  comes  out  f.  '  If  by  this, 
one  month,  by  two  how  many  are  had  ?'  The  number  of  months  is  thus 
found,  5. 

1 10.     Example  :'    From  a  sum  lent  at  the  interest  of  one  in  the  hundred, 
subtracting  the  square  of  the  interest,  the  remainder  was  put  out  at  five  in 

•  The  araouut  of  interest  on  a  hundred  principal  at  the  rate  of  one  per  cent,  is  the  same  with 
that  on  fifty,  at  two;  on  twenty-five,  at  four;  on  twenty,  at  five;  and  on  ten,  at  ten.  Therefore, 
by  the  same  number,  which  multiplying  the  rate  of  the  first  loan  raises  it  to  the  rate  of  the  second, 
the  principal  of  the  first  being  divided  equals  the  second.  For  how  else  should  unequal  principal 
sums  produce  an  equal  amount  of  interest  in  equal  times?  But  the  multiplier  is  the  quotient  ob- 
tained by  dividing  the  rate  of  the  second  loan  by  that  of  the  first.  For  the  first  rate  is  multiplicand; 
and  the  second  rate,  product.  Therefore  the  second  principal,  multiplied  by  the  quotient  of  the 
second  rate  by  the  first,  will  be  the  first  rate.  But  the  second  principal  is  not  known.  A  method 
of  finding  it  follows.  Were  it  arbitrarily  assumed,  the  first  principal  would  be  found  from  it  by 
multiplying  it  by  the  multiplier,  and  the  amount  of  interest  on  the  two  sums  would  be  equal  in 
equal  times  :  but  the  difference  will  not  be  equal  to  the  square  of  the  interest ;  [another  condition 
of  the  problem.]  It  must  be  therefore  treated  differently.  The  square  of  the  interest  being  sub- 
tracted from  the  first  principal,  the  remainder  is  the  second ;  and  conversely  the  square  of  the  in- 
terest added  to  the  second  is  equal  to  the  first.  Consequently,  to  find  the  first  sum,  the  second  is 
to  be  added  to  the  square  of  the  interest;  or  it  is  to  be  multiplied  by  the  multiplier.  The  multi- 
plication may  be  by  portions :  thus,  putting  unity  for  one  portion  of  the  multiplicator,  the  other 
will  be  the  multiplier  less  one  :  and  the  second  principal  multiplied  by  one,  added  to  the  second 
principal  multiplied  by  the  multiplicator  less  one,  or  second  principal  added  to  the  square  of  the 
interest,  will  be  equal  to  the  first  principal.  That  is,  the  square  of  the  interest  is  equal  to  the 
second  principal  multiplied  by  the  multiplicator  less  one.  Hence  the  square  of  the  interest,  being 
divided  by  the  multiplier  less  one,  will  be  the  second  principal,  Though  the  square  of  the  interest 
be  not  known,  it  may  be  had  by  arbitrary  assumption :  and  thereby  the  example  may  be  solved 
completely.  Thus  interest  being  assumed,  and  its  square  being  divided  by  the  multiplicator  less 
one,  the  quotient  is  the  second  principal.  That,  added  to  the  square  of  the  interest,  is  the  first 
principal.  And,  from  the  principal  sum  and  the  amount  of  the  interest,  the  time  is  found.  And 
thus  the  solution  of  question  is  easy  without  putting  (y^vat-t&vat)  a  symbol  for  an  unknown  quan- 
tity. Crishn. 

-  This  example  is  the  author's  own ;  varied  but  little  from  the  preceding  cited  one.  It  is 
omitted  by  Su'ryada'sa,  but  noticed  by  Crishx'a,  who  observes,  that  it  is  designed  to  show  the 
applicableness  of  the  plain  solution  just  exhibited  by  the  author. 


r 


\ 


SIMPLE    EQUATION.  195 

the  hundred.  The  period  of  both  loans  was  alike;  and  the  amount  of  in- 
terest equal. 

Here  the  multiplier  is  5.  The  square  I6,  of  an  assumed  value  of  the 
amount  of  interest  (4)  being  divided  by  the  multiplier  less  one,  4,  the  second 
principal  sum  is  found,  4.  This  being  added  to  the  square  of  the  interest, 
the  first  principal  sum  comes  out  20.  Hence,  by  a  couple  of  proportions,* 
the  time  is  obtained,  20. 

Thus  it  is  rightly  solved  by  the  understanding  alone  :  what  occasion  was 
there  for  putting  (yavat-tdvat)  a  sign  of  an  unknown  quantity  ?  Or  the  in- 
tellect alone  is  analysis  (vija).  Accordingly  it  is  observed  in  the  chapter  on 
Spherics,  '  Neither  is  algebra  consisting  in  symbols,  nor  are  the  several  sorts 
of  it,  analysis.     Sagacity  alone  is  the  chief  analysis  :  for  vast  is  inference.'" 

111.  Example :  Four  jewellers,  possessing  respectively  eight  rubies, 
ten  sapphires,  a  hundred  pearls  and  five  diamonds,  presented,  each  from  his 
own  stock,  one  apiece  to  the  others  in  token  of  regard  and  gratification  at 
meeting :  and  they  thus  became  owners  of  stock  of  precisely  equal  value. 
Tell  me,  friend,  what  were  the  prices  of  their  gems  respectively  ?^ 

Here  the  rule  for  putting  ydvat-tdvat,  and  divers  colours,  to  represent  the 

unknown  quantities,*  is  not  exclusive.     Designating  them  by  the  initials  of 

their  names,  the  equations  may  be  formed  by  intelligent  calculators,  in  this 

manner :  having  given  to  each  other  one  gem  apiece,  the  jewellers  become 

equally  rich  :  the  values  of  their  stocks,  therefore,  are    r    5  *  1  pi  dl 

s   7  rl  p\  d\ 

p97  rl  si  dl 

d  9,  rl  si  pi 

If  equal  be  added  to,  or  subtracted  from,  equal,  the  equality  continues. 
Subtracting  then  one  of  each  sort  of  gem  from  those  several  stocks,  the  re- 
mainders are  equal:  namely  r4,  s6,  p96,  dl.  Whatever  be  the  price  of 
one  diamond,  the  same  is  the  price  of  four  rubies,  of  six  sapphires,  and  of 
ninety-six  pearls.  Hence,  putting  an  assumed  value  for  the  equal  amount 
of  [remaining]  stock,  and  dividing  by  those  remainders  severally,  the  prices 

'  By  the  rule  of  five ;  or  else  by  two  sets  of  three  terms.  Crishn. 

»  G6L  11.  §5. 

'  Already  inserted  in  the  L'Mvati,  §  100.     '  It  is  a  further  instance  of  a  solution  by  putting 
several  sums  equal.'— Sua.     The  problem  is  an  indeterminate  one. 
*  See  the  author's  gloss  on  the  rules  at  the  beginning  of  Ch.  6. 

C  C2 


196  VI'JA-GAN'ITA.  Chapter  IV. 

are  found.     Thus,  let  the  value  be  put  96,  the  prices  of  the  rubies  and  the 
rest  are  found,  24,  I6,  1,  and  96.' 

1 12.  Example  :     A  principal  sum,  being  lent  at  the  interest  of  five  in  the 

hundred  [by  the  month],  amounted   with  the  interest,  when  a  year  was 

elapsed,  to  the  double  less  sixteen.     Say  what  was  the  principal? 

Here  the  principal  is  put  ya  1.     Hence  by  the  rule  of  five       1       12    the 

100  ya  1 
5 

interest  is  found  ya  ^.     This,  added  to  the  principal,  makes  ya  \.     It  is 

equal  to  sixteen  less  than  the  double  of  the  principal,  namely  ya  1  ru  16. 

By  this  equation  the  principal  sum  is  found  40;  and  the  interest  24. 

113.  Example:*  The  sum  of  three  hundred  and  ninety  was  lent  in 
three  portions,  at  interest  of  five,  two  and  four  in  the  hundred;  and 
amounted  in  seven,  ten,  and  five  months  respective!}',  to  an  equal  sum  on  all 
three  portions,  with  the  interest.     Say  the  amount  of  the  portions. 

The  equal  amount  of  each  portion  with  its  interest  is  put  ya  \.  '  If,  for 
one  month,  five  be  the  interest  of  a  hundred ;  then,  for  seven  mouths,  what 
is  the  interest  of  the  same?'  Thus  the  interest  of  a  hundred  is  found  35. 
This,  added  to  a  hundred,  makes  135.  '  If  ol  this  amount  with  interest,  the 
principal  be  a  hundred,  then,  of  the  amount  with  interest,  that  is  measured 
by  ydvat-tdvat,  what  is  the  principal  ?'  The  quantity  of  the  first  portion  is 
thus  found  ya  -f-f..  Again,  '  if,  for  a  month,  two  be  the  interest  of  a  hun- 
dred, then,  for  ten  months,  what  is  the  interest  of  the  same  ?'  Proceeding 
Avith  the  rest  of  the  work  in  the  manner  above  shown,  the  second  portion  is 
ya  f .  In  like  manner,  the  third  portion  is  ya  f .  Their  total  ya  |4  is  equal 
to  the  whole  original  sum  360.  Whence  the  value  of  ydvat-tdvat  is  had  162. 
IJy  this  the  portions  sought  are  "raised:"  namely  120,  135  and  135.  The 
equal  amount  of  principal  with  interest  is  162. 

1 14.     Example:    A  trader,  paying  ten  upon  entrance  into  a  town,  doubled 
his  remaining  capital,  consumed  ten  [during  his  stay]  and  paid  ten  on  his 

'  And  the  amount  of  each  man's  stock,  after  interchange  of  presents,  is  233-  Sua. 

*  Varied  from  an  example  in  arithmetic,  partly  set  forth  in  similar  terms.     Lil.  §91. 


SIMPLE   EQUATION.  197 

departure.     Thus,  in  three  towns  [visited  by  him]  his  original  capital  was 
tripled.     Say  what  was  the  amount?" 

Here  the  capital  is  put  ya  1 .  Performing  on  this,  all  that  is  set  forth  in 
the  question,  the  capital  becomes  on  his  return  from  three  towns  ya  8 
ru  280.  Making  this  amount  equal  to  thrice  the  original  capital,  ya  3,  the 
value  of  ydvat-tdvat  comes  out  56. 

115.  Example:  If  three  and  a  half  mdnas  of  rice  may  be  had  for  one 
dramma,  and  eight  of  kidney-beans  for  the  like  price,  take  these  thirteen 
cdcinis,  merchant!  and  give  me  quickly  two  parts  of  rice,  and  one  of  kid- 
ney-beans :  for  we  must  make  a  hasty  meal  and  depart,  since  my  companion 
will  proceed  onwards.* 

Here  the  quantity  of  rice  is  put  ya  %  and  that  of  kidney-beans  ya\.  '  If, 
for  these  three  and  a  half  mdnas  one  dramma  be  obtained ;  then,  for  this 
quantity  ya  2,  what  is  had  ?'  The  price  of  the  rice  is  thus  found  ya  ^. 
*  If,  for  eight  mdnas  one  dramma,  then  for  this  ya  1  what  ?'  The  price  of 
the  kidney-beans  is  thus  found  ya  \.  The  sum  of  these,  ya  |-|,  is  equal  to 
thirteen  cdcinis ;  or  in  drammas  W.  From  this  equation  the  value  of  ydvat- 
tdvat  comes  out  ^.  Whence,  "  raising"  the  answers,  the  prices  of  the  rice 
and  kidney-beans  are  deduced  \  and  -^^ ;  and  the  quantity  of  rice  and  of 
kidney-beans,  in  fractions  of  a  mdna,  -^  and  -f^. 

1 16.  Example:  Say  what  are  the  numbers,  which  become  equal,  when 
to  them  are  added  respectively,  a  moiety,  a  fifth,  and  a  ninth  part  of  the 
number  itself;  and  which  have  sixty  for  remainder,  when  the  two  other 
parts  are  subtracted. 

Here  the  equal  number  is  put  ya  1.     Hence,  by  the  rule  of  inversion,'  the 

'  This  is  according  to  the  gloss  of  Cri'shna,  and  conformable  with  collated  copies  of  the  text. 

But  Su'rya,  reading  dma-yucta-nirgame  instead  of  dasa-bhuc  cha  nirganie,  omits  the  consumption 

often,  during  stay;  and  confines  the  disbursement,  after  doubling  the  principal,  to   ten  for  duties 

on  export.     The  equation,  according  to  this  commentator,  is  ^a  8    ru  210;  and  the  value  of  j/a,  42. 

ya3    ru      0 

'  Spoken  by  a  pious  riative  of  Gurjara,  going  to  Dw&ricd  to  visit  holy  Cri'shna  ;  and  stopping 
by  the  way  for  refreshment,  but  in  a  hurry  to  proceed,  under  apprehension  of  being  separated  from 
his  fellow  traveller. — Sua.  The  same  example  has  been  already  inserted,  word  for  word,  in  the 
author's  arithmetic.     Lil.  §  97- 

*  lAl.  §  48.    The  fractions  \,  ^,  ^,  become  negative;  and  the  denominator  being  increased  by 


r^  VI'JA-G ANITA.  Chapter  IV. 

several  numbers  are  ya  \,  ya  \,  ya  ■^.  In  this  case,  all  the  numbers,  dimi- 
nished by  the  subtraction  of  the  other  two  parts,  will  be  brought  to  the  same 
remainder,  ya  f  .*  This  being  made  equal  to  sixty,  the  value  oi y&cat-t&vat 
is  obtained  150.  Whence,  by  "  raising"  the  answers,  the  numbers  are  de- 
duced 100,   125  and  135. 

117.  Example:-  Tell  me  quickly  the  base  of  the  triangle,  the  sides  of 
which  are  the  surds  thirteen  and  live,  and  the  base  unknown,  and  the  area 
four? 

In  this  instance,  if  the  base  be  assumed  yavat-tavat,  the  solution  is  tedi- 
ous.* Therefore  the  base  is  put  in  the  triangle  any  way  at  pleasure,*  since 
it  makes  no  difference  in  the  result.  Accordingly  the  triangle  is  here  put 
thus:  rv^       Now,  by  the  converse  of  the  rule  "  half  the  base  multi- 

c5  rv^ 


Cl3 
plied  by  the  perpendicular,  is  in  a  triangle  the  exact  area;"  (Lil.  §  164.  J  the 
perpendicular  is  deduced  from  the  area  divided,  by  half  the  base:  viz.  c-f-f. 
Subtracting  the  square  of  the  perpendicular  from  the  square  of  the  side,  the 
square-root  of  the  difference  is  the  segment  c  -^.  This,  subtracted  from  the 
base,  leaves  the  other  segment  c  VV*.  The  square  of  this  being  added  to  the 
square  of  the  perpendicular,  the  square-root  of  the  sum  is  the  side:  viz.  4.* 
This  [the  triangle  being  turned]  is  the  base  sought. 


the  numerator  for  a  new  denominator,  they  become  4^,  ^,  -^;  which,  being  subtracted  from  ya  1 
rendered  homogeneous,  leave  the  several  original  numbers  ya  f ,  ya  f ,  ya  ^.  Suit. 

^  Ya^  and  j/a^j  (making  j/a  Jg),  subtracted  from  ya  ^,  leave  j/a-,^;  3/a  ^  and  ya -jij  (making 
yaJJ))  subtracted  from  5^0  f,  leave  3^0  ^y;  ya^  and  ya^  (making  ya  ^),  subtracted  from  _yo-^, 
leave  ya-^  :  which,  reduced  to  least  terms,  is  ya^. 

»  This  example  and  the  following  are  introduced  to  show,  that  the  method  of  performing  arith- 
metical operations,  as  taught  in  a  preceding  section  (Ch.  1 .  Sect.  4),  are  not  useless  trouble.   Sua. 

'  It  requires  the  resolution  of  quadratic  equations.  Crishn. 

*  Any  one  of  the  sides  is  made  the  base. 

*  Half  the  base  c  13  is  c  1^.  The  area  ru  4  or  c  I6,  divided  by  that,  is  c  ^.  Its  square  ru  ^, 
subtracted  from  the  square  ru  5  of  the  side  c  5,  or  reduced  to  a  common  denomination  ru  ^^,  leaves 
the  square  ru -^i  of  which  the  square-root  is  c  -^.  This,  subtracted  from  c  13,  leaves  c  '^.  Its 
square  ru  ^,  added  to  the  square  of  the  perpendicular  ru  ^,  makes  ru  ^  or  ru  i6.  Its  root  is 
4.  In  like  manner,  putting  the  other  side  c  5  for  the  base,  the  perpendicular  is  c  ^*.  Its  square 
r««/,  subtracted  from  the  square  ru  13  of  the  remaining  side  (c  13),  leaves  the  segment  c^  (the 


SIMPLE    EQUATION.  199 

118.  Example:  The  difference  between  the  surds  ten  and  five  is  one 
side  of  the  triangle ;  the  surd  six  is  the  other ;  and  the  base  is  the  surd 
eighteen  less  rational  unity,  tell  the  perpendicular. 

Here,  if  the  segment  be  known,  the  perpendicular  is  discovered.  Put  the 
least  segment  i/a  1.  The  base,  less  that,  is  the  value  of  the  other  segment, 
1/al   nil    cl8.     Thus  the  statement  is 

ru  1  cl8 
Subtracting  the  square  of  the  segment  from  the  square  of  its  contiguous 
side,  two  expressions  of  the  square  of  the  perpendicular  are  found  ya  v  1 
ru  15  c  260  and  i/a  »  1  j/a  Q,  ya  c  7'2  ru\3  c  Ti.  They  are  equal:  and, 
equal  subtraction  being  made,  the  two  sides  of  the  equation  become 
rw  28  c512  Here  the  syllable  ^a  [the  symbol  of  the  unknown],  in  the 
ya    2    yac  72 

divisor,  being  useless,  is  excluded;*  and  the  dividend  and  divisor  are  alike 
rw  28  c512  Then,  by  the  rule  for  "  reversing  the  sign  of  a  selected  surd, 
ru    2     c    72 

and  multiplying  both  dividend  and  divisor  by  the  altered  divisor,"  (§  34) 
putting  the  surd  seventy-two  affirmative,  and  multiplying  by  c  4  c  72,  the 
dividend  becomes  c  3136  c2048  c  56448  c  36864.  Taking  the  difference 
between  the  first  and  last,  and  between  the  third  and  fourth,  it  is  reduced  to 
CI8496  c  36992  (or  rw  136  c  36992).  The  divisor  in  like  manner  be- 
comes c  4624  (or  ru  68).  Thus  the  statement  of  dividend  and  divisor  is 
rw  136  c  36992.  The  division  being  made  in  the  manner  directed,  the 
ru    68 

value  oi  yavat-tavat  is  found  rw  2  c8. '  This  is  the  least  segment.  The 
base,  less  this,  is  the  other  segment ;  namely,  n<  1  c  2.  From  the  value  of  the 
unknown  yavat-tavat,  "  raising"  the  expressions  of  the  square  of  the  perpen- 

root  of  ru  });  whence  the  other  segment  is  c  ^.  Its  square  ru  ■/  added  to  the  square  of  the  per- 
pendicular ru  ^  is  ru  ^  or  tk  l6;  the  square-root  of  which  is  4,  (the  other  side,  or  base  required,) 
as  before.  Crisiin. 

'  This  is  the  case  in  all  instances,  for  the  proportion  to  find  the  value  of  the  unknown,  is  "  if 
this  multiple  of  j/a  give  this  known  number,  what  does  i/a  give?"  and  thus,  being  alike  in  both  the 
multiplier  and  divisor,  it  is  excluded  from  both.  The  author,  however,  has  not  noticed  its  exclu- 
sion in  other  instances,  where  the  algebraic  solution  was  in  this  respect  obvious :  but,  in  the  present 
case,  where  the  sign  of  a  selected  surd  is  to  be  reversed,  and  the  dividend  and  original  divisor  to  be 
multiplied  by  the  altered  divisor,  its  presence  in  that  multiplication  would  be  highly  disserviceaLle. 
Its  exclusion  is  now  therefore  specially  noticed.  Crisiin. 


200  VI'JA-GAN'ITA.  Chapter  IV. 

diciilar,  or  subtracting  the  square  of  the  segment  from  the  square  of  its  conti- 
guous side,  the  square  of  the  perpendicular  is  deduced  ru3  c  8.  Its  square- 
root  is  the  value  of  the  perpendicular  rw  1    c  2. ' 

119.  Example:*  Tell  four  unequal' numbers,  thou  of  unrivalled  under- 
standing !*  the  sum  of  which,  or  that  of  their  cubes,  is  equal  to  the  sum  of 
their  squares. 

Here  the  numbers  are  put^a  1,  ya2,  ya  3,  ya^.     Their  sum  \%ya  10.     It 

is  equal  to  the  sum  of  their  squares  ya  v  30.     Dividing  the  two  sides  by  the 

common  measure  yavat-tavat,   the  statement  is  ya  30    ru    0      From  the 

ya   0    ru  10 

value  oi  yavat-tarat  hence  found  as  before,  by  equal  subtraction  [and  divi- 
sion, §  101]  viz.  -\,  the  numbers  are  deduced  by  substitution  of  that  value, 

X     -S-     A     A  * 
3>      3»      3J      3" 

'  The  problem  may  be  solved  by  the  arithmetic  of  surds  without  algebra.  (Li/.  §  l63.)  The 
turn  of  the  sides  is  c5  c  10  c6.  Their  difference  c5  c  10  c6.  Multiplied  together,  the 
product  comprises  nine  terms,  c  25  c  50  c  30  c  50  c  100  c  60  c  30  c  60  c  36;  wherein 
c  30  c  60  c  30  c  60  balance  each  other ;  c  50  and  c  50  added  together  make  c  200 ;  and 
c  25  c  100  and  c  36,  being  rational,  make  ru  5  ru  10  ru  6,  or  summed  ru  9-  The  product 
then  is  r«9     c  200;  to  be  divided  by  the  base  ru  1     c  18.     Thus  the  statement  is  c  8 1     c  200. 

c  i  c  18 
Proceeding  with  this  by  the  rule,  §  34,  and  putting  c  1  positive,  the  dividend  becomes  by  multipli- 
cation c  81  c  200  c  1458  c  3600,  reducible  by  the  difference  of  the  roots  of  the  rationals  81 
and  3600,  and  by  finding  the  difference  of  the  irrationals  200  and  1458,  to  ru  51,  c  578.  The  di- 
visor by  similar  multiplication  iscl  cl8  cl8  c  324  ;  wherein  the  middle  terms  balance  each 
other,  and  the  remaining  two  are  rational,  giving  the  difference  ru  VJ  or  in  the  surd  form,  c  289. 
Hence  the  quotient  of  rM51  c  578  by  ru  17.(0'' '^  289)  is  '■"3  c  2;  which  added  to,  and  sub- 
tracted from,  the  base  ru  1  c  18,  gives  the  sum  and  difference  ru  2  c  8  and  ru  ^  c  32;  the  moie- 
ties whereof  rul  c2  and  rw  2  c  8,  are  the  two  segments  :  and  from  these  the  perpendicular  is 
found  as  before,  ru  1    c  2.  Cafsiix. 

*  These  and  several  following  examples  are  instances  of  the  resolution  of  equations  involving  the 
square,  cube,  or  other  [power]  of  the  unknown,  by  any  practicable  depression  of  both  sides  by 
some  common  divisor,  without  elimination  of  the  middle  term.  Crisiin. 

^  Unequal  or  dissimilar;  unalike. — Sua.  This  is  a  necessary  condition.  Else  unity  repeated 
would  serve  for  an  answer  to  the  question. — Cki'shn. 

*  Su'uYADASA  reads  and  interprets  asama-prajnya,  of  unrivalled  understanding!  CafsHNA- 
BHATTA  notices  that  reading,  as  well  as  the  other,  samach'Mdin  having  like  denominators:  reject- 
ing, however,  this;  as  it  is  not  necessary,  that  it  be  made  a  condition  of  the  problem,  though  it  rise 
out  of  the  solution. 

*  Sumy.     Sura  of  the  squares  ^.  Su'r. 


J 


SIMPLE    EQUATION  201 

In  the  second  example,  the  numbers  are  also  put  ya  \,  ya  2,  ya  3,  ya  4 : 
the  sum  of  their  cubes  is  ya  gh  100,  equal  to  the  sum  of  the  squares  ya  v  30. 
Depressing  the  two  sides  by  the  common  divisor,  square  of  yavat-tdvat ; 
and  proceeding  as  before,  the  numbers  are  deduced  by  substituting  the  value 
o? ydvat-tdvat  (^);  namely,  ^V.  to.  tV  ii* 

120.  Example:  Tell  the  [sides  of  a]  triangle,  of  which  the  area  may  be 
measured  by  the  same  number  with  the  hypotenuse;  and  [of  J  that,  of  which 
the  area  is  equal  to  the  product  of  side,  upright  and  hypotenuse  multiplied 
together. 

In  tliis  case,  the  statement  of  an  assumed  figure  is  n.  ^     Here  half 

ya3       ^ 


ya4 
the  product  of  the  side  multiplied  by  the  upright  is  the  area,  ya  v  6.  It  is 
equal  to  the  hypotenuse  ya  5.  Depressing  both  sides  by  the  common  mea- 
sure ydvat-tdvat,  and  proceeding  as  before,  the  side,  upright  and  hypotenuse, 
deduced  from  the  value  found  of  ydvat-tdvat  (viz.  f)  are  y,  f  and  Y-  Iii 
like  manner,  by  virtue  of  [various]  assumptions,  other  values  also  may  be 
found.  * 

In  the  second  example,  the  same  figure  is  assumed.  Its  area  is  ya  v  6. 
This  is  equal  to  the  product  of  side,  upright  and  hypotenuse,  ya  gh  60. 
Depressing  both  sides  by  the  common  divisor,  square  of  ydvat-tavat,  the 
side,  upright  and  hypotenuse,  found  as  before,  from  the  equation,  are  f,  -j* 
and  ^.     By  virtue  of  assumptions,  other  values  likewise  may  be  obtained.* 


I  0 


121.  Example:  If  thou  be  expert  in  this  computation,  declare  quickly 
two  numbers,  of  which  the  sum  and  the  difference  shall  severally  be  squares; 
and  the  product  of  their  multiplication,  a  cube. 

Here  the  two  numbers  are  put  yav  ^  yav  5;  so  assumed,  that  being  ad- 
ded or  subtracted,  the  sum  or  difference  may  be  a  square.'  The  product  of 
their  multiplication  is  ya  vv  20.     It  is  a  cube.     By  making  it  equal  to  the 

•  Sura  of  the  cubes  f^;  of  the  squares,  f  Jg.  Sub. 

*  That  is,  both  problems  are  indeterminate.  So  likewise  were  those  proposed  in  the  preceding 
stanza,  §  119- 

'  Ya  V  9;  or  ya  v  1. 

D  D 


SOS  VIJ'A-GAN'ITA.  Chapter  IV. 

cube  of  ten  times  the  assumed  y/tvat-tA<oat,  and  depressing  the  two  sides  of 
tlie  equation  by  the  common  divisor,  cube  oi'ydvat-tavat,  autl  proceeding  as 
before,  tbe  two  numbers  are  found  10000  and  12500.' 

122.  Example:  If  thou  know  two  numbers,  of  wliich  the  sum  of  the 
cubes  is  a  square,  and  the  sum  of  their  squares  is  a  cube,  I  acknowledge  thee 
an  eminent  algebraist. 

In  this  instance  the  two  numbers  are  put  ya  v  \,  ya  v  9..  The  sum  of 
tlieir  cubes  is  ya  v  gh  9.  This  of  itself  is  a  square  as  required.  Its  root  is 
ya  gh  3. 

t  Is  not  that  quantity  the  cube  of  a  square,  not  the  square  of  a  cube?  No 
doubt  the  root  of  the  square  of  a  cube  is  cube.  But  how  is  the  root  of  the 
cube  of  a  square,  a  cube?  The  answer  is,  the  cube  of  the  square  is  precisely 
the  same  with  the  square  of  the  cube.*  Hence  if  squares  be  raised  twice,  or 
four,  or  six,  or  eight  times,  their  roots  will  be  so  once,  twice,  thrice,  or  four 
times,  respectively.     It  must  be  so  understood  in  all  cases. 

Now  the  sum  of  the  squares  of  those  quantities  h  ya  v  v  5.  It  must  be  a 
cube.  Making  it  equal  to  the  cube  of  five  times  yavat-tdvat,  and  depres- 
sing the  two  sides  of  the  equation  by  the  common  divisor,  cube  of  yavat- 
tdvat,  and  proceeding  as  before,  the  two  numbers  are  found  6'i5  and  1250.* 

'  From  the  depressed  equation  ^a  20     ru        0  the  value  of  yo  is  found  50.     Its  square  is  2500, 

ya    0     ru  1000 

of  which   the  multiples  yav  4,  and  j/a  v  5  are  10000  and  12500.     In  like  manner,  putting  other 

quantities,  as  ^/a  v  l6  and  yu  z>  20;  and  making  their  product  ^^acr  320  equal  to  cube  of  j/a  20, 

(ya  gA  8000;)  the  equation  depressed  by  the  common  measure  j/a^/i,  is  yfl  320     ru        0     Whence 

ya      O     ru  8000 

the  value  of  ^a  is  25  ;  the  square  of  which  is  625;  and  its  multiples  10000  and  12500  are  the  two 

numbers.     By  varying  the  suppositions,  a  multiplicity  of  answers  is  obtained.  Su'r. 

*  The  cube  of  the  square  is  the  sixth  product  of  the  quantity.  It  is  the  third  product  of  the 
second  product  of  equal  quantities  multiplied.  As  the  cube  of  the  second  product,  so  is  the  second 
product  of  like  multiplication  of  a  third  product.  Therefore,  it  is  also  the  square  of  the  third  pro- 
duct. Crisiin. 

',  The  value  of  ya  being  25.     Or,  putting  the   two  numbers  yo  gi  5,  axiA  ya  gh  10,  the  sum  of 

their  squares  is  a  cube  ya  gh  v  125.     Its  cube  root  is  ya  v  5.     The  sum  of  the  cubes  of  the  same 

quantities  is  ya  gA  gA  1125.     It  is  a  square.     Make  it  equal  to  the  square  of  ya  c  r  75,  viz.  ya  » 

V  V  5625.     Reduce  the  two  sides  of  the  equation  by  the  common  measure  ya  v  v  v.     The  equation 

i»y«  1125     ru       0     Whence  the  value  of  ya  is  found  5  ;  and  the  two  numbers  625  and  1250. 
ya        0     ru  5625 

In  like  manner  a  multiplicity  of  answers  may  be  obtained.  CafsHK'. 


SIMPLE    EQUATION.  «03 

Thus  it  is  to  be  considered,  how  practicably  the  unknown  quantity  [or  its 
power]  may  be  made  a  common  measure. 

123.  Example:  Tell  me,  friend,  the  perpendicular  in  a  triangle,  in 
which  the  base  is  fourteen,  one  side  fifteen,  and  the  other  thirteen.* 

If  the  segment  be  known,  the  perpendicular  is  so.  Put  therefore  yavat- 
tavat  for  the  least  segment,  ya  1 :  the  other  is  the  base  less  ydvat-tdvat,  ya  \ 
ru  14.     Statement: 


14 

The  squares  of  the  sides,  less  the  squares  of  the  contiguous  segments,  are  the 
square  of  the  perpendicular.  They  are  equal  consequently.  Statement  of 
them  for  equal  subtraction  :  yav  I    ya    0     ru  169 .     From  these  the  equal 

ya  V  I     ya  28     ru    29 
square  vanishes;  and  then,  proceeding  as  before,  the  value  of  ydvat-tdvat  is 
found,  5.     From  which  the  two  segments  are  deduced  5  and  9 ;  and  the 
square  of  the  perpendicular  being  "  raised"  [by  substitution  of  that  value]  in 
both  expressions,  it  is  deduced  alike  both  ways  :  viz.  12. 

Here  the  substitution  for  a  square,  is  by  a  square;  and  for  a  cube,  by  a 
cube :  as  is  to  be  understood  by  the  intelligent  calculator. 

124.  Example:*  If  a  bambu,  measuring  thirty-two  cubits,  and  standing 
upon  level  ground,  be  broken  in  one  place  by  the  force  of  the  wind ;  and 
the  tip  of  it  meet  the  ground  at  sixteen  cubits;  say,  mathematician,  at  how 
many  cubits  from  the  root  is  it  broken? 

In  this  case,  the  lower  portion  of  the  bambu  is  the  upright.  Its  value  is 
put  ydvat-tdvat.  Thirty-two,  less  that,  is  the  upper  portion,  and  is  the  hypo- 
tenuse.    The  interval  between  the  root  and  tip  is  the  side.     See 

ya  1 


ru  l6 


•  There  was  not  much  occasion  for  this  example. — Crishh'.  For  the  finding  of  the  perpendicu- 
lar had  been  already  exemplified  by  §118.  That,  however,  was  performed  by  the  arithmetic  of 
surds :  and  this  is  done  by  a  plain  algebraic  calculation. 

'■  The  base,  as  well  as  the  sum  of  the  hypotenuse  and  upright,  being  given,  to  discriminate  them. 
SvR.  and  Crisiin.     See  Lil.  §  148  ;  where  this  example  has  been  already  inserted. 

D  D  2 


204  V  I'J  A-  G  A  N'l  T  A.  Chapter  IV. 

The  sum  of  the  squares  of  the  side  and  upriglit,  ya  v  I  ru  256,  is  equal  to 
the  square  of  the  hypotenuse,  3/fl  v  1  ya64  rw  1024.  The  equal  squares 
vanishing,  and  [the  usual  process  being  pursued]  as  before,  the  value  of 
y&vat-tavat  is  found  12.  Whence  the  upright  and  hypotenuse  are  deduced 
by  substitution  of  that  value,  12,  20.  In  like  manner,  if  the  sum  of  the 
hypotenuse  and  side  be  given,  as  in  the  example  "  A  snake's  hole  is  at  the 
foot  of  a  pillar,'"'  [they  may  be  discriminated]  also. 

1 25.  Example  :*  In  a  certain  lake  swarming  with  ruddy  geese  and  cranes, 
the  tip  of  a  bud  of  lotus  was  seen  a  span  above  the  surface  of  the  water. 
Forced  by  the  wind,  it  gradually  advanced,  and  was  submerged  at  the  dis- 
tance of  two  cubits.     Compute  quickly,  mathematician,  the  depth  of  water. 

In  this  case,  the  length  of  the  stalk  of  the  lotus  is  the  depth  of  water. 
Its  value  is  put  ya\.  It  is  the  upright.  That,  added  to  the  bud  of  the  lotus, 
is  the  hypotenuse,  ya  f    ru  \.    The  side  is  two  cubits.     See  1  ru2 

y»l    yfal     ruj 

Here  also,  the  sum  of  the  squares  of  the  side  and  upright,  yav  I  ru  4,  be- 
ing made  equal  to  the  square  of  the  hypotenuse  yav  \  ya\  ru  -»-,  the  depth 
of  water,  which  is  the  value  of  the  upright,  is  found  ^  ;  and  the  hypote- 
nuse *y'. 

126.  Example:'  From  a  tree  a  hundred  cubits  high,  an  ape  descended 
and  went  to  a  pond  two  hundred  cubits  distant:  while  another  ape,  vaulting 
to  some  height  oft'  the  tree,  proceeded  with  velocity  diagonally  to  the  same 
spot.  If  the  space  travelled  by  them  be  equal,  tell  me  quickly,  learned  man, 
the  height  of  the  leap,  if  thou  have  diligently  studied  calculation. 

The  equal  distance  travelled  is  300.  The  measure  of  the  leap  is  putya  L 
The  height  of  the  tree  added  to  this  is  the  upright :  the  equal  distance  tra- 
velled, less  ydxsat-td'cat,  is  the  hypotenuse.     The  interval  between  the  tree 

'  Lil.  §  150.     See  further  a  note  on  §  140  of  this  treatise. 

*  The  difference  between  the  hypotenuse  and  upright,  as  well  as  the  side  (base)  being  given,  to 
find  the  hypotenuse  and  upright. — Sua.  and  Cri'shn.  See  Lil.  §  153,  where  the  same  example  i» 
inserted.     See  likewise  Lil.  §  152. 

'  This  also  is  found  in  the  LUi-Mi,  §  155.  It  is  borrowed  with  some  variation  from  Bhahme- 
CUPTA  or  bis  conmuntator.     Brahm.  12.  §  39- 


SIMPLE    EQUATION.  «0i 


'■^\yai  ru300 


and  the  well  is  the  side.     See  ya  i 

ru  100 

i 

ru  200 

Making  the  sum  of  the  squares  of  upright  and  side  equal  to  the  square  of 
the  hypotenuse,  the  measure  of  the  leap  is  found  50.* 

127.  Example:*  Tell  the  perpendicular  drawn  from  the  intersection  of 
strings  stretched  mutually  from  the  roots  to  the  summits  of  two  bambus 
fifteen  and  ten  cubits  high  standing  upon  ground  of  unknown  extent.' 

Here,  to  effect  the  solution,  the  value  of  the  ground  intercepted  between 
the  bambus  is  arbitrarily  assumed :  say  20.  Put  the  value  of  the  perpendi- 
cular let  fall  from  the  intersection  of  the  strings  ya  1.     See 


20 

*  If,  to  the  upright  fifteen,  the  side  be  twenty,  then  to  one  measured  by 
ydvat-tdvat  \f\viX  will  be  the  side?'  Thus  the  segment  contiguous  to  the 
less  bambu  is  found  ya  \.  '  If,  to  the  upright  ten,  the  side  be  twenty,  then, 
to  one  measured  hy  ydvat-t mat,  what  will  be  the  side?'  Thus  the  segment 
contiguous  to  the  greater  bambu  is  found  ya  2.  Making  the  sum  of  these, 
ya  *3°  equal  to  twenty,  ru  20,  the  perpendicular  comes  out  6;  the  value  of 
yavat-tdvat.  Whence,  by  substitution  of  this  value,  the  segments  are  de- 
duced 8  and  12. 

Or  the  segments  are  relative  [that  is,  proportionate]  to  the  bambus;  and 
their  sum  is  the  base.*  As  the  sum  of  the  bambus  (25)  is  to  the  sum  of  the 
segments  (20);  so  is  each  bambu  (15  and  10)  to  the  segments  respectively 
(12  and  8).     They  are  thus  found;  and,  from  them,  by  a  proportion,'  the  per- 

'  And  hence  thie  value  of  the  hypotenuse,  250. 

*  Like  the  preceding,  this  too  is  repeated  from  the  Lildvati,  §  l60. 

*  The  ground  intercepted  between  the  bambus  is  expressly  said  to  be  of  unknown  extent,  to^ 
intimate  that  the  distance  is  not  necessary  to  the  finding  of  the  perpendicular.  Crishn. 

*  As  the  bambu  becomes  greater  or  less,  so  does  the  segment.  It  may  be  found  therefore  by  the 
role  of  three :  '  as  the  sum  of  the  bambus  is  to  whole  base,  so  is  one  bambu  to  the  particular  seg- 
ment.' CRfsiiN. 

'  As  a  side,  equal  to  the  base,  is  to  an  upright;  which  is  the  less  bambu,  so  is  a  side,  equal  to  the 
greater  segment,  to  the  perpendicular.  The  less  bambu  is  the  upright,  the  base  is  the  side,  and 
the  string  passing  from  the  tip  of  the  less  bambu  to  the  root  of  the  other  bambu  is  the  hypotenuse ; 
by  virtue  of  the  figure:  and  [in  the  small  triangle]  the  greater  segment  is  side,  and  the  perpendi- 


206  V  r J  A-G  A  N'l  T  A.  Chapter  IV. 

pendicular  is  deduced  (6).     What  occasion  then  is  there  for  [putting  a  sym- 
bol of  the  unknown]  yavat-tdvat  ? 

Or  the  product  of  the  two  bambus  multiplied  together,  being  divided  by 
their  sum,  will  be  the  perpendicular,  whatever  be  the  distance  between  the 
bambus.'  What  use  then  is  there  in  assuming  a  base?  This  will  be  clearly 
understood  by  the  intelligent,  after  stretching  strings  upon  the  ground  [to 
exhibit  the  figure]. 

cular  is  upright.     In  like  manner,  proportion  is  to  be  made  with  the  less  segment  and  greater 
bambu.  Crishn. 

*  As  the  sum  of  the  bambus  is  to  the  base,  so  is  the  greater  bambu  to  the  segment  contiguous  to 
it  ?  Then,  '  as  the  base  is  to  the  less  bambu,  so  is  the  greater  segment  to  the  perpendicular.' 
Here  the  base,  being  both  dividend  and  divisor,  vanishes;  and  the  product  of  the  two  bambus, 
divided  by  their  sum,  is  the  perpendicular.  Crish:/. 


CHAPTER   V. 


QUADRATIC,  ^c.  EQUATIONS. 

Next  equation  involving  the  square  or  other  [power]  of  the  unknown  is 
propounded.  [Its  re-solution  consists  in]  the  elimination  of  the  middle 
term,'  as  teachers  of  the  science''  denominate  it.  Here  removal  of  one  term, 
the  middle  one,  in  the  square  quantity,  takes  place  :  wherefore  it  is  called 
elimination  of  the  middle  term.  On  this  subject  the  following  rule  is  deli- 
vered. 

128 — 130.  Rule:  When  a  square  and  other  [term]  of  the  unknown  is 
involved  in  the  remainder;  then,  after  multiplying  both  sides  of  the  equa- 
tion by  an  assumed  quantity,  something  is  to  be  added  to  them,'  so  as  the 
side*  may  give  a  square-root.     Let  the  root  of  the  absolute  number  again  be 

'  Mad'hyamdharatia ;  from  mad'hyama  middlemost,  and  dkaraiia  a  taking  away  or  (apanayana) 
removal, — Cri'shn.  or  (nisa)  a  destroying, — Su'r.  that  is,  elimination.  The  resolution  of 
these  equations  is  so  named,  because  it  is  in  general  efTected  by  making  the  middle  term  (twice 
the  product  of  the  roots,  §26)  disappear  from  between  two  square  terms. — Sua.  and  Crishn.  ; 
and  note  on  "  equation,"  Ch.  4. 

*  Acharyas  ;  ancient  mathematicians  C&dya-ganaca)  :  as  ARYA-BiiArr'A  and  the  son  of  Jishn'u 
[Brahmegupta]  and  Cuaturve'da  [Prit'hudaca-swa'mi],  Su'r. 

'  This  is  not  exclusive :  in  some  cases  the  two  sides  are  to  be  reduced  by  some  common  divisor; 
and  in  some  instances  an  assumed  quantity  is  to  be  subtracted  from  both  sides.  Crishn. 

♦  So  as  each  side  of  the  equation  may  yield  a  square-root.     Both  being  rendered  such,  the 

root  of  the  known  is  then  to  be  made  equal  to  the  root  of  the  unknown  side Su'r.     However,  if 

the  absolute  number  be  irrational,  its  root  may  be  put  in  the  form  of  a  surd.    See  Crishn.  cited 
in  note  1  next  page. 


a08  VIJ'A-G ANITA.  Chapter  V. 

made  equal  to  the  root  of  the  unknown  :  the  value  of  the  unknown  is  found 
from  that  equation.'  If  the  solution  be  not  thus  accomplished,  in  the  case 
of  cubes  or  biquadrates,  this  [value]  must  be  elicited  by  the  [calculator's] 
own  ingenuity. 

130.  If  the  root  of  the  absolute  side  of  the  equation  be  less  than  the 
number,  having  the  negative  sign,  comprised  in  the  root  of  the  side  involving 
the  unknown,  then  putting  it  negative  or  positive,  a  two-fold  value"  is  to 
be  found  of  the  unknown  quantity :  this  [holds]  in  some  cases.' 

'  When  on  one  side  is  the  unknown  quantity ;  and  on  the  other  the  absolute  number ;  then, 
since  they  are  equal,  the  absolute  number  is  the  value  of  the  unknown:  as  already  shown.  But, 
for  the  purpose  of  a  division  of  the  remaining  absolute  number,  it  is  requisite  that  the  unknown 
should  stand  separate.  The  equation,  therefore,  must  be  so  treated  ;  as  that  such  may  be  the 
case.  If  to  equal  sides  then  equal  addition  be  made,  or  from  them  equal  subtraction;  or  if  equal 
multiplication  or  equal  division  of  them  take  place ;  or  extraction  of  their  roots,  or  squaring  of 
them,  or  raising  to  the  cube  or  other  [power]  ;  there  is  no  loss  of  equality  :  as  is  clear.  Now,  if 
a  square  or  other  [power]  of  the  unknown  be  on  one  side,  and  number  only  on  the  other,  the  un- 
known cannot  stand  separate  without  extraction  of  the  root.  The  roots,  therefore,  of  both  sides 
are  to  be  extracted  consistently  with  their  equality :  and,  that  being  done,  the  roots  also  will  be 
equal.  Therefore  it  is  said,  "  after  multiplying  both  sides  by  an  assumed  quantity,  something  is 
to  be  added  to  them."  Crisiik. 

An  equation  comprising  a  single  colour  (or  symbol  of  unknown  quantity)  being  prepared  as  be- 
fore directed,  when,  after  equal  subtraction,  division  is  next  to  be  made  (§  101),  if  on  the  side  of 
the  unknown  the  square  and  other  terra  of  the  unknown  remain,  then  both  sides  are  to  be  multi- 
plied by  some  quantity,  and  something  is  to  be  added  ;  so  as  both  sides  may  furnish  squares.  The 
roots  of  both  being  then  extracted,  let  equal  subtraction  be  again  made;  and,  that  being  done, 
the  value  of  the  unknown  is  obtained  by  division.  The  principle  of  the  process  is,  that,  if  the  re- 
sidue (or  prepared  equation)  comprise  the  square  and  other  term  of  the  unknown,  the  solution  can 
be  then  only  effected,  when  the  square  is  the  only  term  of  the  unknown;  and  that  can  only  be 
when  the  root  of  the  square  is  extracted.  Accordingly  it  is  said  "so  as  the  side  may  give  a  square- 
root."  Thus,  the  root  of  the  side  of  the  equiition  comprising  the  square  of  the  unknown  being 
extracted,  the  remainder  (^  26)  of  the  compound  square,  that  is,  the  middle  term,  which  stands 
between  the  square  of  ihe  unknown  and  square  of  number,  is  exterminated.  Sua. 

*  M&na,  miti,  unmAna,  or  unmiti;  measure,  value;  root  of  the  equation.     See  §  1/. 

*  Making  the  known  number  on  the  side  of  the  equation  involving  the  unknown  term,  positive, 
a  value  of  the  unknown  is  to  be  found  :  then,  making  the  same  negative,  another  value  of  the 
unknown  is  to  be  deduced  :  and  thus,  both  ways,  the  condition  of  the  question  is  answered. 
Bearing  this  in  mind,  the  author  has  said  in  another  place,  '  There  are  two  hypotenuses,  &c.' 

SuR. 
Demonstration :     When    equal    subtraction    from    equal  sides  take*  place,   if  there   be  a 


QUADRATIC,    &c.   EQUATIONS.        '  209 

131.     ISrid'hara's  rule  on  this  point :  '  IMultiply  botli  sides  of  the  equa- 
tion by  a  number  equal  to  four  times  the  [coeflicient]  of  the  square,  and 

number,  negative,  on  the  side  of  the  unknown  ;  then,  by  the  rule  for  changing  the  sign  of  the 
subtrahend  (§  5),  the  sum  of  the  absolute  numbers  on  the  two  sides  will  be  the  value  :  but,  if  the 
number  be  positive  on  the  unknown  side,  then,  by  same  rule,  the  difference  of  the  quantities  is  the 
value.  When  it  is  thus  discovered  how  many  times  the  sura  or  difference  of  the  absolute  quanti- 
ties is  greater  than  the  difference  of  the  terms  of  the  unknown,  the  value  of  the  unknown  is  ob- 
tained, being  that  which  the  sum  or  difference  so  many  times  measures.  Thus  both  answer  the 
conditions  of  the  question  ;  because  such  multiple  of  the  divisor  balances  the  dividend.  [Ld. 
§  17-]  But,  if  the  value  of  j/dval-tdrat  be  too  little  with  reference  to  the  given  number  specified 
in  the  example,  it  is  unsuitable.  With  a  view  to  this,  the  author  has  said  at  the  close  of  the  rule, 
It  holds  "  in  some  cases."  (§  130).  Sua. 

If  the  root  of  the  known  quantity  exceed  the  absolute  number  comprised  in  the  root  on  the  side 
of  the  unknown,  why  should  not  there  be  a  two-fold  value  in  this  instance  also,  by  the  same  rea- 
soning as  in  the  other  case?  Hear  the  reply.  In  the  instance,  where  the  number  being  negative, 
the  unknown  is  positive,  that  number  must  be  subtracted  from  the  absolute  side,  that  the  remainder 
of  the  unknown  may  be  positive;  the  number  becomes  therefore  affirmative;  and  there  is  no  incon- 
gruity. But  in  the  second  case,  where,  the  number  being  positive,  the  unknown  is  negative,  the 
unknown  must  be  subtracted  from  the  other  side  of  the  equation,  to  become  affirmative ;  and  the 
number  on  the  absolute  side,  being  subtracted  from  that  comprised  in  the  root  e.xtracted  from  the 
unknown  side,  becomes  negative  :  and,  if  it  be  the  greater  of  the  two,  the  value  is  negative.  The 
second  value  conse<iuently  is  every  way  incongruous.  Hence  -the  rule  (§  130).  When  the  tenor 
of  the  condition  is  "  unknown  less  number,"  if  that  is  to  be  squared,  the  term  of  the  simple  un- 
known comes  out  negative,  because  the  number  [which  multiplies  it]  is  so.  In  such  case  when 
the  square-root  is  extracted,  number  only  is  negative,  not  the  unknown  :  for  it  is  certain  that  the 
number  is  negative  in  the  condition  as  proposed.  If  the  unknown  were  put  negative,  the  side  of 
the  equation  would  be  negative  ;  for  it  cannot  be  affirmative  while  the  greater  quantity  is  sub- 
tractive.  Or,  admit  that  it  is  affirmative  in  some  cases;  still  it  would  differ  from  the  side  of  equa- 
tion that  is  consistent  with  the  condition  of  the  problem.  Such  being  the  case,  how  can  it  be  equal 
to  the  second  side  which  is  one  consistent  with  that  condition?  Therefore  a  value,  coming  from 
such  an  equation,  must  be  incongruous ;  because  it  is  negative :  for  people  do  not  approve 
a  negative  absolute  number.  Hence,  in  such,  an  example,  although  the  root  of  the  known  quan-' 
lity  be  less  than  the  negative  number  in  the  root  of  the  unknown  side  (§  130),  there  cannot  be  a 
two-fold  value  :  for  a  value,  grounded  on  the  assumption  of  the  number  being  affirmative  [contrary 
to  the  tenor  of  the  condition]  must  be  incongruous.  In  like  manner,  if  the  tenor  be  "  the  number 
less  the  unknown  squared,"  the  unknown  alone,  not  the  number,  will  be  the  negative  in  the  root : 
by  parity  o/  reasoning.  Therefore,  in  this  instance  also,  there  cannot  be  a  two-fold  value  :  for  a 
value,  grounded  on  the  assumption  of  the  number  being  negative,  will  be  incongruous.  It  is  thus 
in  many  various  ways.  Sometimes,  by  subtraction  of  the  addition  or  other  means  it  is  the  reverse. 
Sometimes,  by  reason  of  the  unknown  being  naturally  negative,  though  the  root  might  possibly  be 
two-fold,  the  second  is  incongruous.  Accordingly  the  author  has  said  indefinitely,  "This  holds 
in  some  cases."    See  an  example  of  the  incongruity  of  the  second  value,  §  140.     See  likewise  an 

E  Ji 


810  VIJ'A-GAN'ITA.  Chapter  V. 

a<ld  to  them  a  number  equal  to  the  square  of  the  original  [coefficient]  of 
the  unknown  quantity.'     (Then  extract  tlie  root.")' 

instance  in  the  chapter  on  the  three  problems  (SirSniani,  Ch.3,  §  100),  where  the  question  is  pro- 
posed as  one  requiring  the  resolution  of  a  quadratic  equation;  and  the  answer  (Jb.  §  101)  shows, 
that,  in  taking  the  roots  of  the  two  sides  of  the  equation,  the  unknown  has  been  taken  negative  and 
the  absolute  number  positive:  for,  if  the  number  were  taken  negative,  the  answer  would  come  out 
differently.  Thus  by  the  reasoning  here  set  forth,  the  congruity  or  incongruity  of  a  two-fold  value 
is  to  be  every  where  understood  :  and  the  author's  remark,  it  holds  in  some  cases  (§  1 30),  is  justified. 

Crisiin. 
'  That  is,  multiply  both  sides  by  the  quadruple  of  the  number  belonging  to  the  square  of  the 
unknown  ;  and  add  to  both  sides  the  square  of  the  number  which  belonged  to  the  unknown  previous 
to  that  multiplication.  This  being  done,  the  side  involving  the  unknown  must  furnish  a  square- 
root  :  and  the  second  side  of  the  equation,  being  equal  to  it,  should  do  so  likewise.  Else  of 
course  the  instance  is  an  imperfect  one. — Crishn.  If  the  known  side,  nevertheless,  do  not  fur- 
nish a  root,  it  must  be  taken  in  the  form  of  a  surd. — Ibid.  Sr/d'hara's  rule,  having  reference 
both  to  the  unknown  and  to  its  square,  is  applicable  only  in  the  case  where  the  same  side  of  equa- 
tion comprises  the  square  of  the  unknown,  and  the  unknown  too.  In  any  other  case  means  of  ob- 
taining a  root  must  be  devised  by  the  intelligent  calculator  exercising  his  own  ingenuity.* — Ibid. 

*  This  insertion  is  according  to  the  reading  which  occurs  and  is  expounded  in  the  commentary 
of  Su'ryada'sa,  avyacta-varga-rupair  yuctau  pacshau  tato  tnUlam:  "both  sides  are  to  have  added, 
numbers  equal  to  the  square  [of  the  coefficient]  of  the  unknown.  Then  the  root  [is  to  be  extract- 
ed]." CRisiiNA-BHATTA's  reading  and  RAMA-CRfsHNA's,  with  which  their  exposition  too  is  con- 
formable, and  which  has  been  followejl  in  the  preceding  part  of  the  version  of  the  text,  differs 
widely:  purvffxyactasya  criteh  sama-mp6ni  cshipet  tayor  eva.  Collated  copies  of  Bha'scara's  text 
agree  with  this :  but  the  variation  is  marked  in  the  margin  of  one  exemplar. 

^  Demonstration  :  After  preparing  the  equation  by  equal  subtraction,  if  the  square  of  the  un- 
known and  the  simple  unknown  be  on  one  side,  and  absolute  number  only  on  the  other ;  the  first 
side  of  the  equation  cannot  by  any  means  furnish  a  root  without  some  addition.  For,  if  the  un- 
known alone  be  squared,  the  square  of  the  unknown  will  be  the  single  result :  but,  if  ihe  unknown 
with  number  added  to  it,  be  squared,  the  result  will  be  [three  terms]  square  of  the  unknown,  un- 
known, and  number:  but,  in  the  proposed  case,  two  terms  only  being  present,  namely  square  of 
the  unknown,  and  unknown,  it  is  not  the  square  of  any  quantity.  Therefore,  number  must  be 
added.  By  subtraction  of  the  unknown,  the  square  of  the  unknown  remaining  a  single  term,  would 
furnish  a  root :  but  then  the  other  side  consisting  of  [two  terms]  unknown  and  number,  would 
not  afford  one.  If  the  term,  containing  the  square  of  the  unknown,  give  a  root,  the  addition  only 
of  a  number  is  needed.  But,  if  it  do  not  afford  a  root,  that  term  must  be  multiplied  or  divided 
by  some  quantity.  Addition  to  it  will  not  answer;  for  the  other  side,  with  equal  addition,  will 
yield  no  root.  Nor  should  a  term  of  the  unknown  be  added  to  both  sides :  for  tliat  would  be 
troublesome.     Besides,  if  the  coefficient  of  the  unknown  be  two,  what  multiple  of  the  square  shall 

•  Tlie  concluding  remark  must  be  taken  as  relating  to  equations  of  a  higlier  degree :  for  the  oilier  case  of  quadratics 
i>  the  simple  one ;  Suio'uaiia's  rule  suflicing  for  aScctcd  quadratic  equations. 


QUADRATIC,  &c.    EQUATIONS.  211 

132.  Example  :  The  square-root  of  half  the  number  of  a  swarm  of  bees 
is  gone  to  a  shrub  of  jasmin  ;  and  so  are  eight-ninths  of  the  whole  swarm  : 
a  female  is  buzzing  to  one  remaining  male,  that  is  humming  within  a  lotus, 

be  added  ?  If  2,  7,  14,  23,  34,  47,  or  62,  times  the  square  of  the  unknown  be  added,  the  one  side 
will  furnish  a  root,  and  not  the  other.  If  1,  4,  or  the  like  multiple  be  the  addition,  the  first  side 
will  give  no  root.  Nor  will  the  subtraction  of  the  square  serve  :  for  the  square,  being  negative  on 
the  second  side,  will  not  there  afford  a  root.  Nor  should  once,  or  four  times,  the  square  be  added, 
when  the  square  had  3  or  5  [for  coefficient];  but  multiplication  by  2,  6,  &c.  take  place,  when  it 
has  2,  6  and  so  forth  :  for  the  solution  will  not  be  uniform,  but  very  troublesome  ;  since  both  sides 
will  comprise  [three  terms]  square  of  the  unknown,  unknown,  and  number.  Therefore  the  square 
of  the  unknown  is  to  be  only  multiplied  by  some  quantity.  When  that  square,  however,  affords  a 
root,  number  only  needs  to  be  added.  The  question  is,  what  this  additive  number  should  be.  If  the 
-oot  of  the  square  unknown  term  have  1  [for  coefl^cienl],  the  addition  of  the  square  of  half  [the 
coefl^cient  of]  the  unknown  term  must  make  that  side  of  equation  yield  a  root.  For  the  product 
of  one  and  of  half  will  be  half  the  unknown ;  and  twice  that  will  be  equal  to  the  unknown  ;  and 
the  extraction  (§  26)  will  be  equal  without  rem.iinder.  So,  if  [the  coefficient]  of  the  root  be  two, 
the  additive  should,  by  the  same  analogy,  be  equal  to  the  square  of  a  quarter  of  the  [coefficient 
of  the]  unknown  term.  If  it  be  three,  the  additive  should  be  the  square  of  the  sixth  part.  Con- 
sequently the  number  to  be  added  must  be  equal  to  the  square  of  the  quotient  of  the  (ancaj  co- 
efficient of  the  unknown  term  by  twice  the  CancaJ  coefficient  of  the  root  which  the  square  unknown 
term  affords.  But,  if  the  coefficient  of  the  square  unknown  term  do  not  yield  a  square-root,  it 
must  do  so  when  the  term  is  multiplied  by  that  same  coefficient.  Therefore  both  sides  of  the 
equation  are  to  be  multiplied  by  the  coefficient  of  the  square  unknown  term.  Here,  by  the  pre- 
ceding analogy,  to  find  the  additive  number,  the  coefficient  of  the  unknown  term  is  to  be  divided 
by  twice  the  coefficient  of  the  root  of  the  square  unknown  term.  Now  the  coefficient  of  the  root 
is  the  unmulliplied  (or  original)  coefficient  of  the  square  Unknown  term.  Therefore  the  coefficient 
of  the  unknown  term  is  to  be  divided  by  twice  the  original  coefficient  of  the  square  ;  and  is  to  be 
multiplied  by  the  original  coefficient  of  the  square,  as  common  multiplier  of  the  two  sides  of  equa- 
tion. Abridging  the  multiplier  and  divisor  by  the  common  measure,  the  original  coefficient  of  the 
square  unknown  term,  the  result  is  two  for  the  divisor  of  the  original  coefficient  of  the  unknown 
term.  In  like  manner,  where  the  coefficient  of  the  square  unknown  term  yields  a  root  without 
previous  multiplication,  there  also  both  sides  being  multiplied  by  that  coefficient,  and  a  number 
equal  to  the  square  of  half  the  previous  coefficient  of  the  simple  unknown  term  being  added,  a 
root  is  had  :  for  the  reasoning  holds  indifferently.  Both  sides,  then,  by  this  process  being  made 
to  afford  roots,  if  they  be  further  multiplied  by  four  to  avoid  a  fraction,  there  is  no  detriment  to 
their  square  nature.  The  square  unknown  term  then,  being  multiplied  by  four,  the  coefficient  of 
its  root  is  doubled.  The  coefficient  of  the  simple  unknown  term  is  to  be  divided  by  that.  The 
divisor  then  is  four  times  the  original  coefficient  of  the  square.  Now  the  common  multiplier  of 
the  equation  is  just  so  much.  Multiplier  and  divisor  then  being  equal,  both  vanish  ;  and  the  ad- 
ditive number  is  the  square  of  the  original  coefficient  of  the  simple  unknown  term.         Crishn. 

£  E  2 


fil2  VI'JA-GAN'ITA.  Chapter  V. 

in  which  he  is  confined,  having  been  alhired  to  it  by  its  fragrance  at  night. 
Say,  lovely  woman,  the  number  of  bees.' 

Put  the-  number  of  the  swarm  of  bees  ya  v  2.  The  square-root  of  half  this 
is^fl  1.  Eight-ninthsof  the  whole  swarm  are  3/at7  ij*.  The  sum  of  the  square- 
root  and  fraction,  added  to  the  pair  of  bees  specified,  is  equal  to  the  amount 
of  the  swarm,  namely  ya  r  2.  Reducing  the  two  sides  of  the  equation  to  a 
common  denomination,  and  dropping  the  denominator,  the  equation  is 
yav  \%  yaO  ru  0  and,  subtraction  being  made,  the  two  sides  are 
yavl6   ya9    ru  IS 

yav  2    ya  9     ru    0      Multiplying  both  tliese  by  eight,   and  adding  the 

ya  vO    yaO     rw  1 8 

number  eighty-one,  and  extracting  both  roots,  the  statement  of  them  for  an 

equation  is  ya  A   ru    9     Whence  the  value  ydvat-tavat  comes  out  6.     By 
ya  0   ru  15 

substituting  the  square  of  this,  the  number  of  the  swarm  of  bees  is  found  72. 

133.  Example:  The  son  of  Prit'ha,  exasperated  in  combat,  shot  a 
quiver  of  arrows  to  slay  Carn'a.  With  half  his  arrows  he  parried  those  of 
his  antagonist ;  with  four  times  the  square-root  of  the  quiver-full,  he  killed 
his  horse ;  with  six  arrows  he  slew  Salya  ;  with  three  he  demolished  the 
umbrella,  standard  and  bow  ;  and  with  one  he  cut  off  the  head  of  the  foe. 
How  many  were  the  arrows,  which  Arjuna  let  fly?'^ 

In  this  case  put  the  number  of  the  whole  of  the  arrows  ya<o  \.     Its  half 

is  ya  V  ^.  Four  times  the  square-root  are  ya  4.    The  specified  arrows  are  ru  10. 

Making  the  sum  of  these  {ya  v  ^  ya4   rw  10)  equal  to  this  quantity  yav  \; 

reducing  both  sides  of  the  equation  to  a  common  denomination,  dropping 

the  denominator,  making  subtraction  as  usual,  adding  sixteen  to  both  sides 

of  the  equation  [j/a  v  I   yaS  rul6      extracting  the  square-roots,  and  making 
yavO  yaO  ru  36] 

these  again  equal  [ya  1    ru4>      the  y&]\ic  of  yavat-tdvat  h  foimd  \0.     From 
ya  0    ru  6] 

which,  by  substitution,  the  number  of  arrows  comes  out  100. 

1 34.  Example :     Of  the  period  [series]  less  one,  the  half  is  the  first  term  j 

'  This  example  is  repeated  from  the  Lildvati,  §  68. 
*  This  also  occurs  in  the  Lildvati,    67. 


QUADRATIC,    &c.    EQUATIONS.  213 

a  moiety  of  the  first  term  is  the  increase  [common  difference] ;  and  the  sum 
[of  the  progression]  is  the  product  of  increase,  first  term  and  period  muhi- 
phed  together,  and  augmented  by  the  addition  of  its  seventh  part..  Tell  the 
increase,  first  term,  and  period.' 

Here  the  period  is  put  ya  4  rii  \;  the  first  term  ya  2  ;  the  common  differ- 
ence ya  1.  The  product  of  their  multiplication  augmented  by  its  seventh 
partisj^a^^  %^  yav  y.  This  amount  of  the  progression  is  equal  to  its 
sum  found  by  the  rule  {Lil.  \  119)  wz.ya  gh  8  yav  10  ya  2.  Depressing 
both  sides  by  their  common  divisor  ydvat-tdvat,  reducing  them  to  a  common 
denomination,  and  dropping  the  denominator,  and  then  making  subtraction, 

the  two  sides  of  the  equation  become  ya  v  8    ya  54    ra   0     From  these  mul- 

yav  Q   ya   0    rw  1 4 
tiplied  by  eight,  and  having  the  square  of  twenty-seven  added  to  them,  the 

square-roots  being  extracted,  are^yaS    ru9.7      Equating  these,  the  value  of 

ya  0    ru  29 

yavat-tdvat  is  found  from  the  equation,  7;  and  the  substitution  of  that  value 

gives  the  first  term,  common  difference,  and  number  of  terms,   14,  7  and  29. 

135.  Example:  What  number  being  divided  by  cipher,  and  having  the 
original  quantity  added  to  the  quotient  and  nine  subtracted  from  this  sum," 
and  the  consequent  remainder  being  squared  and  having  its  square-root  added 
to  that  square,  and  the  whole  being  then  multiplied  by  cipher,  will  amount 
to  ninety  ? ' 

Here  the  number  is  put  ^fl  1.  Tliis  divided  by  cipher,  isj/a-i.  (The  ad- 
dition and  subtraction  being  made,*  it  is  still  ya  \.     This  squared  is  ya  v  -^. 

'  An  example  of  the  sura  of  an  arithmetical  progression.     See  Lil.  Ch.  4. 

*  The  version  is  according  to  Su'ryada'sa's  reading  of  the  text :  but  CuisHNA-BiiAirTA  ap- 
pears to  have  read,  as  does  Ra'ma-crisiin'a,  '  having  fcd^i'^  ten  millions  added  or  subtracted;' 
riiih  cotya  yuctu  't'haxonitah,  instead  of  rasir  adya-yucto  naxonitah.  Collated  copies  differ :  but  the 
variation  is  noticed  in  the  margin  of  one. 

'  This  and  the  following  are  examples  of  the  arithmetic  of  cipher.  See  §  12 — 14,  and  LU, 
S  44—46. 

♦  CRisHNA-nHATTA  seems  here  also  to  have  read,  '  with  ten  millions  added  or  subtracted  :' 
and  the  quantity,  being  a  fraction  with  cipher ,lbr  its  denominator,  remains  unaltered  by  the  addi- 
tion of  a  finite  quantity  (§  l6).     But   Suryada'sa,  though  he  cites  §  l6  and  Lit.   §45,   deduces 

from  the  conditions  of  the  question  the  equation,  ya  u  4   3/a  34    rtt72     by  adding  to  j/a  ;;  4   ya^G 

yav  0  ya    0    ru  90 


214  VI'JA-GAN'ITA.  Chapter  V. 

The  root  added  to  it  makes  3^«  iy -J-  i/a  ■^.  Multiplied  by  cipher,  the  multi- 
plier and  divisor  being  alike  vanish,  leaving  i/av  I  yal.)  Hence  multiply- 
ing [the  equation]  by  tour  and  adding  one,  and  proceeding  as  before,  the 
number  is  found  9- 

136.  Example:  Say  what  is  the  number,  which  having  its  half  added 
to  it,  and  being  multiplied  by  cipher,  and  the  product  squared,  and  added 
to  twice  the  root  of  that  square,  and  this  sum  being  divided  by  cipher,  be- 
comes fifteen  ? 

The  number  is  put  ya  1 .  This,  having  its  half  added  to  it,  becomes  i/a  f. 
Being  multiplied  by  cipher,  it  is  not  to  be  made  nought  but  to  be  considered 
as  multiple  of  cipher,  further  operations  impending.  Wherefore  i/a  f  "0, 
being  squared,  and  having  twice  the  root  added,  becomes  ya v  ^0  i/a  ^  0. 
This  is  divided  by  cipher :  and  here,  as  before,  the  multiplier  being  0,  and 
the  divisor  0,  both  multiplicator  and  divisor,  as  being  equal,  vanish ;  and 
the  quantity  is  unaltered:'  viz.  yav^  3/«  V-  Equating  with  fifteen,  re- 
ducing to  a  common  denomination,  and  then  dropping  the  denominator,  the 
two  sides   of  the   equation  by    preparation  become  yavQ   ya  \Q    ru   0 

ya  V  0  ya  0  rii  60 
Adding  four,*  and  extracting  the  square-roots,  the  value  of  ydvat-tdvat  by 
equal  subtraction  comes  out  2. 

137.  Example  :  a  stanza  and  a  half.  What  is  the  number,  learned  man, 
■which  being  multiplied  by  twelve  and  added  to  the  cube  of  the  number,  is 
equal  to  six  times  the  square  added  to  thirty-five  r* 

The  number  is  put  ya  1.  This  multiplied  by  twelve,  and  added  to  the 
cube  of  the  number,  is  ya  gh  1  i/a  12.  It  is  equal  to  this  other  quantity 
yav  6    ru  35.     Subtraction  being  made,  the  first  side  of  the  equation  be- 

ru  81,  its  TooiyaZ    ru9;  and  thence  [doubling  the  equation,  and]  proceeding  by  the  rule  §  131, 

he  derives  the  equation  of  the  roots  ya  8    ru  34    From  which,  by  the  usual  process,  he  finds  9 

ya  0    ru  38 

for  the  value  o{  i/a.  One  of  the  copies  of  the  text,  which  have  been  collated  for  the  present  trans- 
lation, omits  the  whole  of  this  intermediate  work  here  enclosed  within  a  parenthesis. 

•  Lil.  §  44—45. 

*  The  additive  four  sufficing  to  make  them  afford  square-roots.  Crishi/. 

'  It  has  been  said  "  If  the  solution  be  not  thus  accomplished,  [as]  in  the  case  of  cubes  or  bi- 
quadrates,  the  value  must  be  elicited  by  the  [calculator's]  own  ingenuity."  §  129.  The  present  and 
the  following  are  instances  of  the  application  of  that  aphorism.  Sua. 


QUADRATIC,  kc.  EQUATIONS.  215 

comes  yaghl  yav  6  ya  12;  and  the  other  side,  ru  35.  Adding  the  nega- 
tive number  ciglit  to  both  (or  subtracting  eight  from  both  sides')  and  ex- 
tracting the  cube-roots,*  they  are  i/a  1    ru  2     From  the  equation  of  these 

yaO   ru  3 
asrain,  the  amount  of  the  number  is  found  5. 

138.  Example:  If  thou  be  conversant  with  operations  of  algebra,  tell 
the  number,  of  which  the  biquadrate,  less  double  the  sum  of  the  square  and 
of  two  hundred  times  the  simple  number,  is  a  myriad  less  one. 

■  Let  the  number  be  put  7/a  1 .     This,  multiplied  by  200,  is  T/a  200.     Added 
to  the  square  of  the  number,  it  is  yav  I    ya  200  ;  which,  multiplied  by  two 
becomes  j/a  v  2    ya  400.     The  biquadrate  of  the  number,  less  that,  \s  yawl 
yav  2    ya  400.     This  is  equal  to  a  myriad  less  unity.     The  two  sides  of  the^ 
equation  are  yav  v  1    yav2    ya  400     ru        0      Here  adding  to  the  first 

■  yaw  0  ya  vO  ya  0  ru  9999 
side  ydvat-tdvat  four  hundred,  with  unit  absolute,  it  yields  a  root  (ya  "c  1 
ru  i):  but  the  other  side  (^a400  ru  10000)  does  notj  and  the  solution 
therefore  is  not  accomplished.  Hence  ingenuity  is  in  this  case  called  for. 
Adding  then,  to  both  sides  of  the  equation,  square  of  yavat-tdvat  four, 
ydvat-tdvat  four  hundred,  and  a  single  unit  absolute,  roots  of  both  may  be 
extracted.  Thus  the  first  side,  with  the  additive,  becomes  ya  v  v  1  yav  2, 
ru\.  The  other  side,  with  it,  exhibits  j/a  i>  4  j^a400  ru  lOOOO.  Their 
roots  are  yav  I  ru\  and  ya2  rw  100.  From  these,  equal  subtraction 
being  made,  the  two  sides  of  the  equation  are  deduced  ya  v  I    ya  2,     ru   0 

yavO    ya  0    ru  99 
Again  adding  unit  to  each  side,  the  roots  are  obtained  ya  I     ru    \      From 

ya  0     7'u  10 

which  equation  the  vdXvxe  of  ydxiat-tdvat  comes  out  11.  In  like  instances 
the  value  must  be  elicited  by  the  sagacity  of  the  intelligent  analyst. 

1 39.  Example  :  The  eighth  part  of  a  troop  of  monkeys,  squared,  was 
skipping  in  a  grove  and  delighted  with  their  sport.     Twelve  remaining 


t> 


'  A  variation  of  the  text  is  here  put  in  a  parenthesis.  The  effect  is  the  same;  and  one  reading 
serves  to  interpret  the  other. 

^  By  the  analogy  of  the  rule  for  the  extraction  of  the  square-root  (§  26)  taking  the  roots  of  the 
cube  of  the  unknown  and  of  the  absolute  number,  and  subtracting  from  the  remainder  thrice  the 
product.s  [of  the  square  and  simple  quantities]  two  and  two.  Si/r. 


216  VI'JA-GAN'ITA.  Chapter  V. 

were  seen  on  the  hill,  amused  with  chattering  to  each  other.     How  many 

M'erc  they  in  all  r ' 

In  this  case  the  troop  of  monkeys  is  put  ya  1.     The  square  of  its  eighth 

part,  added  to  twelve,  being  equal  to  the  whole  troop,  the  two  sides  of 

equation  dXQ  yax! -^   yaO    tm  12      Reducing  these  to  a  common  denomi- 
yax!  0     ya  I    rii   0 

nation,  dropping  the  denominator,  and  making  equal  subtraction,  they  be- 
come yav\    ya  64     ru      0     From  these,  with  the  square  of  thirty-two 
.    yavQ    ya    0    ru  768 

added  to  them,  the  roots  are  extracted  ya  1    ru  32     Tlie  number  of  the 

ya  0    ru  \6 
root  on  the  absolute  side  is  here  less  than  the  known  number,  with  the  nega- 
tive sign,  in  the  root  on  the  side  of  the  unknown.     Making  it  then  negative 
and  positive,  a  two-fold  value  oi ykvat-tavat  is  thence  obtained,  48  and  16. 

140.*  Example:  The  fifth  part  of  the  troop  less  three,  squared,  had 
gone  to  a  cave ;  and  one  monkey  was  in  sight,  having  climbed  on  a  branch. 
Say  how  many  they  were?' 

Here  the  troop  is  put  i/a  1.  Its  fifth  part  is  ya^.  Less  three,  it  is  ya\ 
ru  y .  This  squared  \%  ya*o  ^  y^  if  ^"  W-  With  the  one  seen  (-|f).  it  is 
yav  -^  ya^  ru  ^-^.     This  is  equal  to  the  troop  ya  1.     Reducing  these 

*  This  instance  is  relative  to  the  rule  (§  130)  which  admits  a  two-fold  value  of  the  unknown, 
when  the  square-root  on  the  absolute  side  is  less  than  the  known  number,  comprised  in  the  square- 
root  on  the  other  side  of  the  equation.  Su'r.  and  Cafsux. 

•  SuRYADASA  here  interposes  an  example,  the  same  which  is  inserted  \n  the  lAl&vati,  §150. 
It  is  not,  however,  found  in  collated  copies  of  the  V'lja-gaiiita,  nor  noticed  in  this  place  by  Crishn'a- 
BHATTA,  nor  by  Ra'ma-ckishn'a.  The  solution,  as  wrought  by" the  first  named  commentator, 
follows  :  '  Put  ya  1  for  the  side  of  the  triangle  or  distance  between  the  snake's  hole  and  the  point 
of  meeting.  If  this  side  be  subtracted  from  the  sura  of  the  side  and  hypotenuse,  namely  27,  the 
remainder  is  the  hypotenuse:  it  is  ya  1  ru  27.  Its  square,  yav  1  ya  54  ru  729,  is  equal  to  the 
sura  of  the  squares  of  the  side  put  ya  I  and  upright  given  9  :  naraely  ya  v  \.  ru  81.  liqual 
subtraction  being  made,  the  value  of  ya  is  found,  12.  Thus  the  distance  between' the  hole  and 
point  of  meeting  comes  out  12  cubits  ;  and  this,  subtracted  from  the  distance  from  the  hole  of  the 
spot  where  the  snake  was  seen,  namely  27,  leaves  the  equal  progress  of  the  two,  15. — Sur.  The 
example,  as  is  apparent,  is  here  out  of  place,  and  should  have  been  noticed  by  the  scholiast,  where 
the  author  has  himself  referred  to  it,  in  his  gloss  on  §  124. 

'  Two  instances  are  here  given  to  show,  that  the  twofold  value  is  admissible  in  some  cases  only. 

Crisiin. 


QUADRATIC,    &c.    EQUATIONS.  217 

sides  of  equation  to  a  common  denomination,  dropping  the  denominator,  and 
making  equal  subtraction,  the  equation  becomes  ?/aw  1   ya55   ru      0     Mul- 

yavO  ya    0  ru  250 
tipJying  by  four,  and  adding  a  number  equal  to  the  square  of  fifty-five  (3025), 
the  roots  extracted  are  ya  2   ru  55      Here  also  a  two-fold  value  is  found 

ya  0  ru  45 
as  before,  50  and 5.     But  the  second  is  in  this  case  not  to  be  taken:  for 
it  is  incongruous.     People  do  not  approve  a  negative  absolute  number.' 

141.  Example:  The  shadow  of  a  gnomon  twelve  fingers  high  being 
lessened  by  a  third  part  of  the  hypotenuse,  became  fourteen  fingers  long. 
Tell  quickly,  mathematician,  that  shadow. 

In  this  case  the  shadow  is  put  ya  1.  This,  less  a  third  of  the  hypotenuse, 
becomes  fourteen  fingers.  Hence,  conversely,  subtracting  fourteen  fingers 
from  it,  the  remainder  is  a  third  of  the  hypotenuse,  ya  1  ru  14.  This  then, 
multiplied  by  three,  is  the  hypotenuse ;  ya3  ru  42.  Its  square  is  ya  v  9 
ya  252  ru  1764;  which  is  equal  to  this  other  value  of  the  square  of  the  hy- 
potenuse,^ yav  I     ru  144.     Equal  subtraction  being  made,   the  two  sides  of 

'  The  second  value  being  five,  its  fifth  part,  one,  cannot  have  three  subtracted  from  it.     There 

is  incongruity ;  to  indicate  which  the  author  adds  expressly,  '  the  second  is  in  this  case  not  to  be 

taken.'  Su'r. 

.    Put  \ya  5  for  tlie  troop  of  monkeys.     Its  fifth  part  is  yai.     Less  three,  it  is  3/a  1    ru3.     This 

squared  is  j/a  f  1     i/a6    ru  ()■     With  one  added,  it  is  ya  v  I    ya6    ru  10;  and  is  equal  to  ya  5. 

Equal  subtraction  being  made,  the  equation  h  yav  I    ^a  1 1     ru    0      Multiplying  by  four,  and 

ya  V  0    ya    0    r«  1 0 

superadding  the  square  of  1 1,  it  becomes  yav  'i    ya  44    ru  121      Here,  since  the  known  numb«r 

yavO    ya    0    ru    81 

was  proposed  as  negative  [i.e.  subtractive]  the  root  should  be  taken,  under  the  reasoning  before 
stated  [gloss  on  §  130]  ya2  ru  H;  not  yai  ru  \l.  The  root  of  the  second  side  of  the  equation 
is  9.*  By  further  equation  of  the  roots,  the  value  of  ya  comes  out  10.  Whence  the  number 
of  the  troop  is  deduced  50.  But,  if  the  known  number  (11)  be  made  positive,  the  value 
ofya  will  be  1  ;  and  the  whole  quantity  5.  From  its  fifth  part  (one),  three  cannot  be  subtracted.  If 
indeed  the  enunciati<m  of  the  question  were,  "  The  filth  part  of  the  troop  taken  from  three"  [in- 
stead of"  less  three"],  the  second  value,  and  not  the  first,  would  be  taken.  For  the  fifth  part  of 
the  first  value  cannot  be  deducted  from  three.  Crisiin. 

*  For  the  shadow  being  the  side  of  a  rectangular  triangle,  and  the  gnomon  twelve  fingers  in 
length  being  the  upright :  {Siromani:  Book  1,  Ch.  3.)  the  rule,  that  the  square-root  of  the  sum  of 
their  squares  is  the  hypotenuse,  is  universally  known.  Su'r. 

•  Or  else  9.     But  with  this  toot  the  aw.hor  would  take  j/a  2    full   instead  of  j/o  S   rull. 

F   F 


$18  VI'JA-G ANITA.  Chapter  V. 

the  equation  become  yav^  ya  252      ru    0       Multiplying    by  two,   and 

yav  0    ya  0     ru  1620 

superadding  the  square  of  the  number  sixty-three,  the  roots  are  ya  4   ric  63 

ya  0    I'll  27 

Making  these  again  equal,  and  proceeding  as  before,  the  value  o^ yavat-tdvat 

is  obtained  two-fold  *-^  and  9.     The  second  value  of  the  shadow  is  less  than 

fourteen :  therefore,   by  reason  of  its  incongruity,  it  should  not  be  taken. 

Hence  it  was  said  "  this  holds  in  some  cases."  (§  130.) 

It  is  in  derogation  of  the  maxim  delivered  in  Padmanabha's  algebra,'  on 

this  subject : 

142.  "  When  the  root  of  the  absolute  side  is  less  than  the  known  number 
being  negative  on  the  other  side,  making  it  positive  and  negative,  the  value 
comes  out  two-fold."  * 

143 — 144.  Example:  What  are  the  four  quantities,  friend !  which  with 
two  severally  added  to  them,  yield  square-roots  ;  and  of  which  the  products, 
taking  them  two  and  two,  contiguous,'  become  also  square  numbers  when 
eighteen  is  added :  and  which  are  such,  that  the  square-root  of  the  sum  of 
all  the  roots  added  to  eleven,  being  extracted,  is  thirteen  ?  tell  them  to  me, 
algebraist ! 

In  this  case,  the  number,  which,  added  to  two  quantities,  renders  them 
square  numbers,  is  the  additive  of  the  [original]  quantities.  That  additive, 
multiplied  by  the  square  of  the  difference  of  the  roots,  is  the  additive  of  the 
product.  That  is,  the  product  of  those  two  ({uantities,  with  the  addition  of 
tljis  [additive]  must  yield  a  square-root.  The  products  of  the  roots  of  the 
quantities,  taken  two  and  two  contiguous,  being  lessened  by  a  deduction  of 
the  additive  of  the  quantities,  are  the  roots  of  the  products  of  those  quanti- 
ties.* This  principle  must  be  understood  in  all  [similar]  cases.  In  the  pre- 
sent instance,  the  additive  of  the  products  is  nine  times  the  additive  of  the 
simple  quantities.     The  square-root  of  nine  is  three.     Therefore,  the  roots 

'  Padmaiu'ibha-V'ija. 

*  The  quotation,  as  copied  by  the  commentator  Su'ryada'sa,  contains  the  very  reservation 
for  which  Bha'scara.  contends  "  the  value  will  be  two-fold  sometimes:"  daid'hd  minan  cwachit 
bhavet,  instead  uf  dicividhufpadj/ate  rnili/i,  the  reading  which  occurs  in  collated  copies. 

'  The  first  and  second  are  to  be  multiplied  together;  and  the  third  and  fourth. — Sua.  First 
and  second  ;- second  and  third  ;  third  and  fourth.  Crishm. 

♦  For  the  demonstration  of  both  these  positions,  see  note  to  §  145. 


QUADRATIC,    &c.    EQUATIONS.       .  219 

of  the  quantities  are  [arithmeticals]  differing  by  the  common  difference 
three :  i/a  1  t/a  I  ru3  ya\  ru6  ya\  ru  9-  The  products  of  these,  two 
and  two,  less  the  additive  of  the  simple  quantities,  being  computed,  are 
the  square-roots  of  the  products  of  the  quantities  with  eighteen  added. 
Hence  the  roots  of  the  products  as  above  described  are  yav  1  ya3 
ru2;  yav  I  yaQ  ru  16;  yav  I  ya\5  ru59,}  The  sum  of  all  these 
and  of  the  original  roots  h  yav  3  ya  3\  ru  84.  Making  this,  with 
eleven  added  to  it,  equal  to  the  square  of  thirteen  ;  multiplying  the  sides  of 
the  equation  (after  equal  subtraction)  by  twelve;  and  superadding  the  square 

of  thirty-one,  the  roots  are  ya6    rw  31      From  the  equation  of  these  again, 

ya  0    rM  43 
the  value  o? ydvat-tavat  \s  found  2.     Whence  the  roots  of  the  quantities  are 
deduced,    2,  5,  8  and  II.     Of  course   the  original  quantities   (being  the 
squares  of  those  roots,  less  the  additive  of  the  simple  quantities,)  are  2,  23, 
62  and  1 19. 

On  this  subject  there  is  a  maxim  of  an  original  author  :* 

145.     '  So  many  times  as  the  additive  of  the  products  contains  the  additive 

■  Su'ryada'sa,  employing  only  the  first  of  the  foregoing  positions,  as  it  is  contained  also  in  the 
maxim  cited  from  an  earlier  writer  (§  145),  deduces  the  algebraic  expressions  for  the  roots  of  the 
products  from  those  of  the  simple  quantities :  *  The  additive  of  the  products  (18)  is  nine  times  the 
additive  of  the  simple  quantities  (2).     Its  square-root  is  3.     The  simple  roots  then  are  ya\     ruO 

ya  I     ru  3 

ya  I     ru6 

ya  i     ru  9 

Andthequantitiesdeduced  bysquaringtheseandsubtractingtheadditivetwOjarej/acl    ya   0    ru   i 

yav  I  ya  6  ru  7 
yav  I  yal2  ru 34 
yav  I    ya  13    ru79 

The  products  of  the  contiguous  two  and  two,  (^"^  ^' '' 1     ^"^f  ,f    ^'^   ,f    ^^   J,^     ''"       ^ 

.,        ,  ,,    ,  '<yavvl     yagklS    yav    41     ya   284     ru    250 

with  eighteen  added,  are  iyavv\     yag/,30    yav  113    ya\560     r«2704 

The  square-roots  of  these  three  are  j^ai;  1     3^0    3     ru    2      Their  sum  (ya»  3   ya  27    ru66)    with 

ya  V  I     ya    9    »"«  1^ 
ya  V  I    ya  15     ru  52 

the  sum  of  the  simple  roots  (ya4    ru  18)  or  yav  3  ya31    rw  84,  with  11  added,  is  equal  to  the 

square  of  13,  or   I69.     The   equation   thenisj/at;3    j/a31     ru    95     and,  after  subtraction,  be^ 

yav  0    ya    0    ru  I69 
comes  ya  v  3    ya  31    ru   0      Proceeding  as  usual  (§  131),  the  value  of  y&vat-tdvat  comes  out  2.' 
yavO    ya   0    ru  74  Su'u. 

*  Neither  Bha'scara,  nor  his  commentators,  intimate  the  name  of  this  ancient  and  (Mya) 
original  author,  whose  words  are  here  quoted. 

F  I-  2 


S£0 


Vl'JA-G  AN'ITA.  Chapter  V. 


of  the  simple  quantities,  by  the  square-root  of  that  [submultiple]  as  a  common 
difference,  the  unknown  (juantities  are  to  be  put  [in  arithmetical  progression] 
and  to  be  stjuarcd,  and  then  diminished  by  subtraction  of  the  additive." 

This  supposition  of  apposite  quantities  required  much  dexterity  in  com- 
putations. 

U6.  Example :  Say  what  is  the  hypotenuse  in  a  plane  figure,  in  which 
the  side  and  upright  are  equal  to  fifteen  and  twenty?  and  show  the  dcmon- 
stiation  of  the  received  mode  of  computation.'' 

Here  the  hypotenuse  is  put  ya  1.  Turning  the  triangle,  the  hypotenuse 
is  made  the  base ;  and  its  side  and  upright  are  the  sides :  and  the  side  and 
upright  in  each  of  the  triangles  situated  on  either  side  of  the  perpendicular 

•  The  demonstration  of  this,  and  of  Biiascaua's  corresponding  position  with  the  further  one 
sulyoined  by  him,  is  given  by  the  commentator  CufsHNA  :  '  If  the  square-root  of  a  quantity  in- 
creased by  an  additive  be  known,  then  by  inversion  the  quantity  is  the  square  of  that  root,  less  the 
additive ;  and  is  also  known.     From  the  first  root  the  first  quantity  is   found  pv\    a  I  ;  and,  in 
like  manner,  from  the  second  root,  the  second  quantity  dn  1    a  1.    That,  which,  added  to  their 
product,  makes  it  a  square,  is  the  additive  of  the  product.     Multiplied  together  their  product  is 
pv.dvbhX    pv.abhi    dv.ahhl    av\.    In  the  second  term,  the  square  of  the  first  root  multiplied 
by  the  additive  is  negative;  and,  in  the  third  terra,  the  like  multiple  of  the  square  of  the  second 
root  is  also  negative.  To  abridge,  put  sum  of  the  squares  of  the  roots  multiplied  by  the  additive  with 
the  negative  sign.    The  first  term  is  the  product  of  squares  of  the  roots  ;  or,  which  is  the  same,  the 
square  of  the  product  of  the  roots.    The  statement  then  is  r  prod,  t)  1   r  »  sum  a  1    a  i>  1.     In  the 
second  of  these  three  terms,  the  sum  of  the  squares  of  the  roots  is  resolvable  into  two  parts  ;  the 
square  of  the  difference  of  the  roots  and  twice  the  product  of  the  roots.     (LU.  §  135.)     The  second 
term  is  thus  resolved  into  two;  namely  the  square  of  the  difference  and  twice  the  product  multi- 
plied by  the  additive  :  and  the  statement  of  all  the  terms  in  their  order  consequently  is  r  prod,  v  1 
rdiff.  r.oi     r  prod,  a  2    av\.     Now  the  number,  which,  added  to  this  product  of  the  quantities, 
makes  it  afford  a  square-root,  is  the  additive  of  the  product.     But  here,  if  the  square  of  the  differ- 
ence of  the  roots  multiplied  by  the  additive  (r  diff.  r.  a  1)  be  superadded,  the  remaining  terms 
r  prod.  V  1     rprod,  a  2    av  \,  will  yield  a  square-root.     It  is  therefore   demonstrated,  that  the 
additive  of  the  simple  quantities,  multiplied  by  the  square  of  the  difference  of  the  roots,  is  additive 
of  the  product ;  and  the  product  of  the  same  roots,   less  the  additive,  will  be  the  root  of  the  pro- 
duct of  the  quantity.     The  same  reasoning  is  applicable  to  the  second  and  third;  and  to  ihe  third 
and  fourth.    Thus  the  root  of  one  quantity  being  put  y{,mt-t&vat,  the  roots  of  all  may  be  rightly 
deduced  from  if  [by  their  common  difference  computed  from  the  additives].  CRfsiiN. 

»  The  question  of  the  hypotenuse  is  here  put,  solely  to  inquire  the  principle  of  the  solution  of 

,,.        ,,  Crisus. 

this  problem. 


QUADRATIC,    &c.    EQUATIONS.  221 

let  fall  in  the  proposed  triangle,  are  analogous  to  the  former.'  Hence  the 
proportion  :  '  if,  when  yavat-tdvat  is  hypotenuse,  this  be  the  side  (1,5),  then, 
the  hypotenuse  being  fifteen  (equal  to  the  original  side),  what  is  ?'  Thus 
the  side  [of  the  smaller  triangle]  is  found,  and  is  the  segment  contiguous  to 
the  original  side  :    ru  225      Agaiji,  if  ydvat-tavat  being  hypotenuse,  this 

ya  1 
be  the  upright  (20),  tlien,  the  hypotenuse  being  twenty  (equal  to  the  ori- 
ginal upright),  what  is  ?'     Thus  the   upright  [of  the  other  little  triangle]  is 
found,  and  is  the  segment  contiguous  to  the  original  upright  :^  ru  400     The 

y»  1 

sum  of  the  segments  is  equal  to  hypotenuse :  and  from  so  framing  the  equa- 
tion, the  value  of  hypotenuse  is  deduced,'  the  square-root  of  the  sum  of  the 
squares  of  the  side  and  upright,  viz.  25.  Hence,  substituting  the  value, 
the  segments  are  found  9  and  16;  and  thence  the  perpendicular  12.     See 


Or  the  solution  is  thus  otherwise  propounded.  The  hypotenuse  is  j/a  I. 
Half  the  product  of  the  side  and  upright  is  the  area  of  the  triangle:   150. 

'  They  are  proportional  ('rtnK;'M/)aJ .  Crishn. 

*  The  greater  side  being  here  named  the  upright,  (while  either  side  might  have  been  so  denomi- 
nated ;  Lil.  §  133.)  in  the  original  triangle,  the  greater  side  of  the  one  small  triangle  must  be  taken 
as  the  upright  found  by  the  proportion  '  as  yhat-taval  is  to  the  original  upright,  so  is  an  hypote- 
nuse of  that  length  to  a  quantity  sought :'  it  is  the  segment,  which  is  the  greater  side  of  this  tri- 
angle; not  the  perpendicular,  which  is  its  less  side.  So  the  smaller  side  of  the  other  little  triangle 
must  be  taken  as  the  side  found  by  the  proportion,  '  as  yAvat-tivitt  is  to  the  original  side,  so  is  a  hy- 
potenuse of  that  length  to  a  quantity  sought :'  and  it  is  the  segment,  this  being  the  least  side  of  the 
triangle  ;  not  the  perpendicular  which  is  here  the  greater  side.  Crishn. 

^  CafsiiNA  gives  the  solution  by  literal  symbols  alone.      By  the  first  proportion  ya  1  |  bhu  1  | 
bhu  1  I   the  segment  contiguous  to  the  side  is  bhu  v  I      By  the  other  proportion,  ya  I  \  co  I  \  co  I  \ 

ya  1 
the  segment  contiguous  to   the   upright  is  co  v  1      The  sum  of  the  segments  bhu  v  \    fo  t'  1   is 

ya\  ya  I 

equal  to  the  base  ya  1.     Reducing  to  a  common  denomination  and  dropping  the  denominator,  the 
two  sides  of  the  equation  become  ya  v   1  Hence  the  square  of  the  hypotenuse  is  equal  to 

bhu  V  I    cov  \ 
the  sum  of  the  squares  of  upright  and  side. — CRfsiiN.     Here  bhu  is  initial  of  bhuja,   the  side  (lit. 
arm);  and  co  of  co/i,  the  upright. 


sc« 


VI'JA-G  ANITA. 


Chapter  V. 


With  four  such  triangles,  another  figure  having  four  sides,  each  equal  to  the 
hypotenuse,'  is  constructed  for  the  purpose  of  finding  the  hypotenuse.     See 


Thus  another  interior  quadrilateral  is  framed ;  and  the  difference  between 
the  upright  and  side  is  the  length  of  its  side.  Its  area  is  25.  Twice  the  pro- 
duct of  the  upright  and  side  is  the  area  of  the  four  triangles,  600.  The  sum 
of  these  is  the  area  of  the  entire  large  figure ;  625.  Equating  this  with  the 
square  o? ydvat-tdvat,  the  measure  of  the  hypotenuse  is  found,  25.*  If  the 
absolute  number,  however,  be  not  an  exact  square,  the  hypotenuse  comes 
out  a  surd  root. 

147.  Rule  :  Twice  the  product  of  the  upright  and  side,'  being  added  to 
the  square  of  their  difference,  is  equal  to  the  sum  of  their  squares,  just  as 
with  two  unknown  quantities.* 

Hence,  for  facility,  it  is  rightly  said  '  The  square-root  of  the  sum  of  the 
squares  of  upright  and  side,  is  the  hypotenuse?'' 

•  The  triangles  are  to  be  so  placed,  as  that  the  hypotenuse  may  be  without;  and  the  upright  of 
one  be  in  contact  with  the  side  of  another :  else,  by  merely  joining  four  rectangular  triangles  [with  the 
equal  sides  contiguous,]  a  quadrilateral  having  unequal  diagonals  [that  is,  a  rhomb]  is  constituted; 
in  which  one  diagonal  is  twice  the  upright ;  and  the  other  double  the  side  of  the  triangle;  instead 
of  a  square  comprising  five  figures  (four  triangles  and  a  small  interior  square).  But,  if  the  upright 
and  side  be  equal,  a  square  only  is  framed,  which  ever  way  the  side  is  placed,  since  there  is  no 
difference  of  the  upright  and  side:  and  in  this  case  there  is  no  interior  square.  Crishn. 

»  In  this  instance  also,  Crisiina  exliibits  the  solution  by  literal  symbols:  '  Area  of  the  tnangle 
bhu.co\.  Multiplied  by  four,  it  is  the  area  of  four  such  triangles,  bhu.co2.  Difference 
bku  \  co\.  Its  square  bkuv  I  bhu.  co  2  cor  1.  This,  which  is  the  area  of  the  interior  square, 
being  added  to  the  area  of  the  four  triangles,  bhu.  co  2,  makes  bhu  vl    co  v  1 ;  the  area  of  the 

,  Crishn. 

entire  square.  ^ 

3  This  is  not  confined  to  upright  and  side ;  but  applicable  to  all  quantities.     (Ld.  §  135.) 

Cri'shn. 

♦  Let  the  two  quantities  be  ya  I  ca  I .  The  square  of  their  diflerence  will  be  ya  v  1  ya.  ca  bh  2 
cavi.    To  this  twice  the  product  ya.  ca  bh  2  being  added,  the  result  is  the  sum  of  the  squares 

Crisiiit. 
ya  t  I    ca  V  i . 

'  See  the  same  rule  expressed  in  other  words  ;  Lil.  §  134-. 


15XJ 
20  X 

/20 
/15 

5 

QUADRATIC,    &c.    EQUATIONS, 
Placing  the  same  portions  of  figure  in  another  form,    see 


148.  Example  :  Tell  me,  friend,  the  side,  upright  and  hypotenuse  in  a 
[triangular]  plane  figure,  in  which  the  square-root  of  three  less  than  the  side, 
being  lessened  by  one,  is  the  difference  between  the  upright  and  hypotenuse. 

In  this  case  the  difference  between  the  upright  and  hypotenuse  is  arbi- 
trarily assumed :  say  2.  Hence,  by  inversion,  (taking  the  square  of  that 
added  to  one  and  adding  three  to  the  square;)  the  side  is  obtained,  12.  Itsi 
square,  or  the  difference  of  the  squares  of  hypotenuse  and  upright,  is  144. 
The  difference  of  the  squares  of  two  quantities  is  equal  to  the  product  of 
their  sum  and  difference.*^  For  a  square'  is  the  area  of  an  equilateral  qua- 
drangle [and  equi-diagonal*].     This  for  example,  is  the  square  of  seven,  49: 


Subtracting  from  it  the  square  of  five,   viz.  25,  the  remainder  is  24. 

7 


See 


5 


Here  the  difference  is  two;  and  the  sum  is  twelve:  and  the  product  of 
the  sum  and  difference  consists  of  24  equal  compartments 

12 

J2 


Thus  it  is  demonstrated,  that  the  difference  of  the  squares  is  equal  to  the 
product  of  the  sum  and  difference.  Hence,  in  the  instance,  the  difference 
of  the  squares,   144,  being  divided  by  the  assumed  difference  of  the  hypo- 

*  Producing  the  line,  the  figure  is  divided  into  two  squares :  one  the  square  of  the  upright;  the 
other  the  square  of  the  side  :  and  their  sum  is  the  area  of  the  first  or  large  square  ;  and  its  square- 
root  is  the  side  of  the  quadrilateral.  Crishn. 

*  Lil.^  135. 

'  Varga,  or  2d  power. 

*  CaiSHNyi. 


224 


VI'JA-G  ANITA. 


Chapter  V. 


tenuse  and  upright,  2,  is  the  sum,  72-'  This  sum,  twice  set  down,  and 
having  the  dift'crence  severally  subtracted,  and  being  halved  according  to 
the  rule  of  concurrence,*  gives  the  upright  and  hypotenuse  35  and  37-  In 
like  manner,  putting  one,  tlie  side,  upright  and  hypotenuse  are  7,  24,  and 
27.  Or,  supposing  four,  they  are  28,  96,  and  100.'  So  in  every  [similar] 
case. 

149.  Rule:  The  difference  between  the  sum  of  the  squares  of  two 
quantities  whatsoever,  and  the  square  of  their  sum,  is  equal  to  twice  their 
product ;  as  in  the  case  of  two  unknown  quantities.* 

For  instance,  let  the  quantities  be  3  and  5.  Their  squares  are  9  and  25. 
The  square  of  their  sum,  6"4.  From  this  taking  away  the  sum  of  the  squares, 
the  remainder  is  30.     See 

3  5  8  5 


n 

— 

5 

8 

"^ 

— 

— 

—" 

— 

n 

— 

~~ 

— 

— 

— 

3 

r 

' 

1 

— 

J 

Here  square  compartments,  equal  to  twice  the  product  are  apparent;  and 
[the  proposition]  is  proved. 

150.  Rule:  The  difference  between  four  times  the  product  and  the 
square  of  the  sum,  is  equal  to  the  square  of  the  difference  of  the  quantities; 
as  in  the  instance  of  unknown  ones.' 

Let  the  quantities  be  3  and  5.  From  the  square  of  their  sum,  taking 
away  four  products'  at  the  four  corners,  there  remain  in  the  middle,  square 

"  See  Lit.  §  57. 

*  LU.  §  5.5. 

'  The  problem  is  an  indeterminate  one. 

*  Let  the  quantities  be  t/al  cal.  The  suip  of  their  squares  is  j/a  »  1  ca  v  I ;  and  the  square  of 
their  sum  ya  v  1  ya.  cabhl  cav\.  The  difference  between  which  is  ya.  ca  bh  2;  or  twice  the 
product  of  the  two  quantities.  CafsHN. 

'  Let  the  two  quantities  be  ya  1  ca  1.  Four  limes  the  product  is  ya.  ca  bh  4.  The  square  of 
ihesumisyatl  ya.cabhl  carl.  From  this  square  talking  four  times  the  product,  the  re- 
mainder is  yav\  ya.cabhk  cav\.  And  this  is  the  square  of  the  difference  of  the  two  quan- 
tities. Crishn. 

*  Rectangles. 


QUADRATIC,    &c.    EQUATIONS. 


225 


compartments  equal  to  the  square  of  the  difference  of  the  quantities ;  and 
[the  proposition]  is  proved.     See 


5 

2 
5 
3 

151.  Example:  Tell  the  side,  upright  and  hypotenuse,  of  which  the 
sum  is  forty,  and  the  product  of  the  upright  and  side  is  a  hundred  and 
twenty. 

Here  twice  the  product  of  the  side  and  upright  is  240.  It  is  the  difference 
between  the  square  of  their  sum  and  the  sum  of  their  squares.'  The  sum 
of  the  squares  of  the  side  and  upright  is  the  same  with  the  square  of  the  hy- 
potenuse.^ Therefore  it  is  the  difference  between  the  square  of  the  sum  of 
the  side  and  upright,  and  the  square  of  hypotenuse;  and  is  equal  to  the  pro- 
duct of  sum  and  difference.  Therefore  this  difference,  240,  divided  by  the 
sum  40,  gives  the  difference  of  hypotenuse  and  the  sum  of  the  side  and 
upright,  viz.  6.  The  sum,  having  thfe  difference  severally  subtracted  and 
added,  and  being  then  halved,  gives  by  the  rule  of  concurrence,'  the  sum  of 
the  upright  and  side  23,  and  the  hypotenuse  17.*  From  the  square  of  the 
sum  of  the  upright  and  side,  namely  529,  subtract  four  times  the  product 
(§  150),  viz.  480,  the  square  root  7  of  the  remainder  (49)  is  the  difference  of 
the  side  and  upright.  From  the  sum  and  difference,  the  side  and  upright 
are  found  by  subtraction  and  addition  and  then  taking  the  moieties:  and 
they  come  out  8  and  15. 

152.  E.xample:'  Tell  me  severally  the  side,  upright  and  hypotenuse, 
the  sum  of  which  is  fifty-six;  and  their  product  seven  times  six  hundred. 

In  this  instance  put  hypotenuse  ya  I .  Its  square  is  i/av  I.  It  is  the  sum 
of  the  squares  of  the  side  and  upright.  The  sum  of  the  three  sides  (hypo- 
tenuse, upright  and  base)  less  hypotenuse  is  the  sum  of  the  upright  and  side; 

'  §  149. 
«  §  146. 
'  Lit.  §  55. 

*  For  the  sura  of  two  sides  must  exceed  the  hypotenuse.  (_LU.  §  l6l .)  Crishh. 

'  This  example,  though  overlooited  by  Su'ryada'sa,  is  noticed  both  by  Cri'shna  and  Ra'ma- 
cbishn'a;  and  is  found  in  all  the  collated  copies  of  the  te.\t. 

G  O 


S26  VI'JA-GAN'ITA.  Chapter  V. 

Sf^  I     ru  56.     So  the  product  of  the  three,  divided  by  hypotenuse,  gives  the 
product  of  upright  and  side  ru  4200     By  a  preceding  rule  C§  149)  the  dif- 

1/a  1 
ference  between  the  sum  of  the  squares  (ya  v  1)  and  the  square  of  their  sum 
(i/a  V  I     t/a  112     ru  3136),  namely  j/c  112     ru  3136,  is  equal  to  twice  the 
product  or  ru  8400     First  reducing  to  least  terms  by  the  common  divisor  a 

ya  I 
hundred  and  twelve;  then  bringing  both  sides  of  the  equation  to  a  common 
denomination,  dropping  the  denominator,  making  equal  subtraction,'  and 
superadding  the  square  of  fourteen  to  both  sides  of  the  equation,*  the  value 
of  ydvat-tdvat  is  found,  25.  A  second  value  in  this  case  comes  out  by  way 
of  alternative,  namely  3:  but  it  is  not  to  be  taken  because  it  is  incongruous.* 

In  the  instance,  the  product  of  the  three  sides,  4200,  being  divided  by 
the  hypotenuse  25,  gives  the  product  of  the  upright  and  side,  168.  Thus 
the  sum  of  the  upright  and  side  being  31  (^56  less  25),  the  difference  of  the 
upright  and  side  is  found  by  the  preceding  rule  (§  150)  namely  17.  And 
thence,  by  the  rule  of  concurrence,*  the  side  and  upright  are  deduced  7 
and  24. 

So  in  all  [like]  cases. 

The  intelligent,  by  a  compendious  method,  do  in  some  instances  resolve 
a  problem  by  reasoning  alone.  But  the  grand  operation  is  by  putting  [a 
symbol]  of  the  unknown. 

"  The  text  to  which  Ra'macrishn'a's  commentary  is  appended,  here  exhibits 

Equation  j^a  »  112    ya  3136    ru  0  Abridged  by  112,     i/a  v  I    ya  28     ru    0 

yav  0         yaO  ru  8400  ya  v  0    ya    0     ru75 

•  Some  copies  of  the  text  substitute  the  equivalent  operation  of  multiplying  by  four,  and  adding 
the  square  of  twenty-eight. 

*  See  remark  under  §  141. 

♦  If/.  §55. 


CHAPTER    VI. 


EQUATION  INVOLVING  MORE  THAN  ONE  UNKNOWN 

QUANTITY. 

Next,  Analysis  by  a  Multiliteral  Equation  is  propounded. 

153 — 156.  Rule:  Subtract  the  first  colour  (or  letter')  from  the  other 
side  of  the  equation;  and  the  rest  of  the  colours  (or  letters)  as  well  as  the 
known  quantities,  from  the  first  side:*  the  other  side  being  then  divided  by 
the  [coefficient  of  the]  first,  a  value  of  the  first  colour  will  be  obtained.'  If 
there  be  several  values  of  one  colour,  making  in  such  case  equations  of  them 
and  dropping  the  denominator,*  the  values  of  the  rest  of  the  colours  are  to 
be  found  from  them.'  At  the  last  value,  the  multiplier  and  quotient,  found 
by  the  method  of  the  pulverizer,*  are  the  values  of  both  colours,  dividend 

'  See  the  author's  following  comment;  and  the  note  upon  it. 

*  That  is,  the  two  sides  of  the  equation  are  to  be  so  treated,  as  that  a  single  colour  may  remain 
on  one  side:  which  is  effected  by  equal  subtraction  of  all  the  rest  of  the  terms  on  that  side  from 
both;  and  of  the  term  similar  to  it  on  the  other.  It  is  not  necessary  to  restrict  the  choice  of  the 
particular  colour  :  but,  as  there  is  no  motive  for  passing  by  the  first,  that  is  selected  to  be  retained; 

Crishn. 
'  This  division  is  the  equivalent  of  the  proportion,  in  which  one  of  the  unknown  is  the  third 
term,  and  a  multiple  of  it  is  the  first ;  to  find  the  value.     See  note  on  §  157. 

*  After  reduction  to  a  common  denomination. 

'  This  sufiices  for  problems  admitting  but  one  solution.  What  follows,  relates  to  indeterminate 
problems. 

*  An  answer  to  an  indeterminate  problem  being  required  in  whole  numbers.  Else  arbitrarj^ 
values  may  be  put  for  all  the  remaining  unknown  terms  in  the  last  and  single  value  of  an  unknown. 
In  such  case  the  answer  is  easy  :  but  is  probably  fractional.  CRimti. 

G  g2 


228  VrJA-GAN'ITA.  ChapteuVI. 

and  divisor:'  if  there  be  other  colours  in  the  dividend,  put  for  them  any 
arbitrarily  assumed  values;  and  so  find  those  two.  By  substituting  with 
these  inverse!}',  the  values  of  the  rest  of  the  colours  are  then  obtained. 
But,  if  a  value  be  fractional,  the  investigation  of  the  pulverizer  is  to  be  re- 
peated; and,  with  that  substituting  for  the  last  colour,  deduce  the  values 
conversely  from  the  first.* 

This  is  analysis  by  equation  comprising  several  colours.' 
In  this,  the  unknown  quantities  are  numerous,  two,  three  or  more.  For 
which  yavat-tavat  and  the  several  colours  are  to  be  put  to  represent  the 
values.  They  have  been  settled  by  the  ancient  teachers  of  the  science:* 
viz.  "  so  much  as"  {yavat-tavat),  black  (cc/flcfl),  blue  («//«•«),  ytWow  {pitaca), 
red  (lohitaca),  green  {haritaca),  white  (swetaca),  yarlegntcd  {chit raca),  tawny 
(capilaca),  tan-coloured  {piugala),  grey  (d'humraca),  pink  (pcitalaca),  white 
(savalaca),  black  [sydmalaca),  another  black  (mechaca),  and  so  forth.      Or 

•  The  colour  or  letter,  appertaining  to  the  divisor,  is  the  quantity  of  w  hich  the  algebraic  expres- 
sion was  the  value ;  its  coetiicient  being  the  divisor  or  denominator. — See  note  to  §  157.  The 
colour  belonging  to  the  dividend  or  numerator,  is  one  comprised  in  that  alaebraic  expression  of  the 
value  of  the  former.  See  note  on  the  author's  comment  below.  One  unknown  is  a  function  of 
the  other. 

*  The  commentator  CkTshna  notices  two  variations,  or  altogether  three  readings  of  this  passage. 
He  prefers  one  as  most  consistent  with  the  author's  own  explanation  of  his  text ;  and  interprets  it 
thus:  If,  in  course  of  substitution,  the  value  of  another  colour  be  had  fractional,  investigation  of  a 
pulverizer  is  to  be  again  performed;  and,  with  that  multiplier,  substituting  for  the  last  colour,  de- 
duce the  values  inversely  from  the  first.  That  is,  with  the  particular  multiplier  termed  pulverizer 
(Ch.  2),  substituting  for  the  colour  contained  in  the  two  or  more  last  values,  again  deduce  the 
values  inversely  from  the  preceding:  meaning  from  the  value  which  contained  a  fractional  one. 
Beginning  thence,  let  inverse  substitution  take  place. 

The  second  reading  is, '  the  other  colour  (or  letter)  is  to  be  found  by  repeating  the  investigation 
of  the  pulverizer;  and  with  that  substituting  for  the  original  [or,  according  to  another  construc- 
tion, for  the  last,  colour]  ;  deduce  the  values  conversely  from  the  first;'  or,  as  the  third  reading 
varies  it,  '  deduce  conversely  the  last  and  the  first.'  It  is  defective  in  either  construction  :  for  the 
pronoun  "  that"  refers  to  the  "  other  colour  (or  letter);"  the  value  of  which  is  found  by  investiga- 
tion of  the  pulverizer:  but  "  the  other"  so  referred  to  is  the  divisor  in  that  investigation:  and  the 
"  last"  colour,  for  which  substitution  is  to  be  made,  is  the  dividend:  and  the  sentence,  therefore, 
according  to  these  readings,  directs  a  substitution  of  vfilue  for  the  wrong  colour.  Crishn. 

^  Anica-varna-sam'tcamna  vija.     See  Ch.  4.  note  on  gloss  following  §  100 — 102. 
"*  FiirvAcMryAik,  by  former  teachers.     What  particular  authors  are  intended  is  unexplained. 
Brahmegupta  employs  names  of  colours  to  designate  the  unknown,  without  any  remark;  whence 
it  appears  that  the  use  was  already  familiar.     See  Braiim.  18.  §  52  d  seq. 


MULTILITERAL    EQUATIONS.  229 

letters*  are  to  be  employed;  that  is  the  literal  characters  c,  &c.  as  names  of 
the  unknown,  to  prevent  the  confounding  of  them. 

Here  also,  the  calculator,  performing  as  before  directed  (Ch.  4)  every 
operation  implied  by  the  conditions  of  the  example,  brings  out  two  equal 
sides,  or  more  sides,  of  equation.  Then  comes  the  application  of  the  rule: 
'  From  one  of  the  two  sides  of  the  equation,  subtract'  the  first  (letter  or) 
colour  of  the  other.  Then  subtract  from  that  other  side  the  rest  of  the  (let- 
ters or)  colours,  as  well  as  the  known  quantities.  Hence  the  one  side  being- 
divided^  by  the  residue  of  the  first  (letter  or)  colour,  a  value  of  the  (letter  or) 
colour  which  furnishes  the  divisor  is  obtained.  If  there  be  many  such  sides, 
by  so  treating  those  that  constitute  equations,  by  pairs,  other  values  are  found. 
Then,  among  these,  if  the  values  of  one  (letter  or)  colour  be  manifold,  make 
them  equal  by  pairs,  drop  the  denominator,*  and  proceeding  by  the  rule 
[§  153],  find  values  of  the  other  (letters  or)  colours :  and  so  on,  as  practicable. 

Thereafter,'  the  number  (coefficient)  of  the  dividend  (letter  or)  colour  in 
the  last  value  is  to  be  taken  as  .the  dividend  quantity ;  and  that  of  the  divi- 

'  Varna,  colour  or  letter :  for  the  word  bears  both  imports.  Former  writers  used  it  in  the  one 
sense,  and  directed  all  the  unknown  quantities  after  the  first  to  be  represented  by  colours.  But 
the  author  takes  it  also  in  the  second  acceptation  ;  and  directs  letters  to  be  employed,  instancing 
the  consonants  in  their  alphabetical  order.  He  appears  tu  intend  initial  syllables.  (See  his  solu- 
tion of  the  problem  in  §  1 U .)  His  predecessors,  however,  likewise  made  use  of  initial  syllables  for 
algebraic  symbols ;  for  instance  the  marks  of  square,  cube  and  other  powers  ;  and  the  sign  of  a 
surd  root:  as  well  as  the  initials  of  colours  as  tokens  of  unknown  quantities. 

^  See§  101. 

'  Ibid. 

*  After  reduction  to  a  common  denominator. 

'  In  the  last  and  single  value  of  the  unknown  denoted  by  a  colour,  if  one  or  more  unknown 
terms  denoted  by  ctdours  be  comprised,  values  might  be  arbitrarily  put  for  all  these  terms  in  the 
dividend ;  and  these  values  being  summed,  and  divided  by  the  denominator,  would  give  the  value 
of  the  first  colour.  It  might  be  either  a  fraction  or  integer,  and  the  values  of  the  rest  would  be 
those  arbitrarily  assumed.  Such  a  solution  is  facile.  But,  if  the  answer  be  required  in  whole 
numbers,  then  reserving  one  colour  put  arl)itrary  values  for  the  rest;  and  thus  a  single  colour  with 
certain  absolute  numbers  will  remain  in  the  dividend.  Now  such  a  value  of  that  colour  is  to  be 
assumed,  as  that  the  coefficient  of  the  colour,  being  multiplied  by  the  assumed  quantity,  and  added 
to  the  absolute  number,  and  divided  by  the  denominator,  may  yield  no  residue:  for  so  the  value  of 
the  first  colour  will  be  an  integer.  This  is  the  very  problem  solved  in  the  investigation  of  a  pulve- 
rizer (Ch.  2).  If  then  a  value  of  the  colour  in  the  dividend  be  putequal  to  the  multiplier  so  found, 
the  colour  appertaining  to  the  divisor  will  be  the  quotient,  and  an  integer.  Hence  the  text,  "  At 
the  last  value,  &c."    (§  154 — 155.)  Ciusiin'. 


230  VI'JA-G ANITA.  Chapter  VI. 

sor  (letter  or)  colour,  as  the  divisor  quantity ;  and  the  absolute  number,  as 
the  additive  quantity:  with  which,  proceeding  by  the  rule  of  investigation 
of  a  pulverizer  (Ch.  2),  the  multiplier,  which  is  so  found,  is  the  value  of  the 
dividend  (letter  or)  colour;  and  the  quotient,  which  is  obtained,  is  that  of 
the  divisor  (letter  or)  colour.  The  reduced'  divisor  and  dividend  [used  as 
abraders  in  the  investigation]  of  these  two  values,  being  multiplied  by  some 
assumed*  (letter  or)  colour,  are  to  be  put  as  additives  [of  the  multiplier  and 
quotient,''  or  values  so  found,]  and  thence,  substituting  their  values  with 
these  additives,  for  those  colours  (or  letters)  in  the  value  of  the  former  colour 
(or  letter),  and  dividing  by  the  denominator,  the  quotient,  which  is  obtained, 
is  the  value  of  the  former  colour  (or  letter).  In  like  manner,  inversely  sub- 
stituting [the  values  thus  successively  found],  the  values  of  the  other  colours 
(or  letters)  are  thence  deduced.  But,  if  there  be  two  or  more  colours  (or 
letters)  in  the  last  value,  then  putting  arbitrarily  assumed  values  for  thera, 
and  substituting  by  those  values  and  adding  the  results  to  the  absolute  num-. 
ber,  the  investigation  of  a  pulverizer  is  to  be  performed. 

In  the  course  of  inverse  substitution,  if  the  values  of  a  colour  (or  letter), 
in  a  value  of  a  preceding  one,  be  fractional,  then  the  multiplier,  which  is 
found  by  a  further  investigation  of  the  pulverizer,  with  the  addition  [of  the 
divisor*]  is  the  value  of  the  dividend  colour  (or  letter).'  Then  substituting 
with  it  for  that  colour  (or  letter)  in  the  last  values  of  colours  (or  letters), 
and  proceeding  by  inverse  substitution,  in  the  preceding  ones,  the  values  of 
the  other  colours  (or  letters)  are  found. 

In  this  [analysis],  when  the  value  of  a  (letter  or)  colour  is  found,  (whether 
that  value  be  a  known  quantity,  or  an  unknown  one,  or  known  and  un- 

•  See  §  54. 

*  The  assumed  colour  represents  the  arbitrary  factor,  introduced  (§  64)  to  make  arbitrary  mul- 
tiples of  the  (abrading)  divisore  additives  of  the  multiplier  and  quotient ;  that  is,  of  the  values  here 
found.  By  substituting  cipher  for  this  assumed  colour,  as  is  frequently  done  in  the  following  exam- 
pies  (§  l60,  l6l,  l63,  &c.),  the  simple  values  are  used  without  the  additives.  It  does  not  represent 
an  unknown  quantity  which  is  sought;  but  a  factor  of  the  divisors,  which  is  to  receive  an  arbitrary 
value:  and  it  serves  to  show  the  relation  of  the  quantities  in  the  manifold  answers  of  an  indetermi- 
nate problem,  the  solution  of  which  is  required  in  whole  numbers.    See  CRfsHN. 

'  See  §64. 

♦  Ibid. 

'  Recourse  is  had  to  this  method,  to  clear  the  fraction :  for  the  same  reason  holds  indifferently. 

CRfSHN. 


MULTILITERAL    EQUATIONS.  ssi 

known  together ;)  and  is  multiplied  by  the  coefficient  of  the  unknown,  the 
removal  or  extermination  of  that  ("literal  character  or)  colour  is  called 
(Uti'hapana)    "  raising"  or  "  substitution."* 

Example :  "  The  quantity  of  rubies  without  flaw,  sapphires  and  pearls," 
&c.  (§  105.) 

In  this  case,  -^wWavk^  yavat-tavat,  &c.  for  the  rates  of  the  rubies  and  the 

rest,  and  making  the  number  of  each  sort  of  gem  with  its  rate  a  multiple, 

and  superadding  the  absolute  number,  the  statement  for  equal  subtraction  is 

ya5    ca  S    ni  7    ruQO      Proceeding  as  directed,  to  "  subtract  the  first  co- 
ya7    ca  9    ni  6    ru  62 

lour,  &c,"  (§  153)  this  single  value  oi ydvat-tdvat  is  obtained  ca\    ni\    rwQS* 

ya9. 
Being  single,  this  same  value  is  "last"  (§  154).     Therefore  the  investigation 
of  the  pulverizer  must  take  place.     In  this  dividend  there  is  a  couple  of  co- 
lours :  wherefore  (§  155)  the  value  o^  ni  is  arbitrarily  put  Unity ;  with  which  ' 
substituting  for  ni,  and  superadding  it  to  the  absolute  number,  there  results 
ca  1    ru  29      Hence,  by  the  rule  of  investigation  of  the  pulverizer,  the 

ya  2 
multiplier  and  quotient,  together  with  the  additives  [deduced  from  their  di- 
visors] are  found  pi  2    ru    1      Then,  substituting  for  pi  by  putting  cipher 

pi  1     ru  14 
for  it,  the  rates  of  the  rubies  and  the  rest  come  out  14,  1,    1.     Putting  one 
for  pf,  they  are  13,  3,   1;  assuming  two,   12,    15,   1;  or,  supposing  three, 
11,  7,  1.     Thus,    by  virtue  of  suppositions,  an  infinity  of  answers  is  ob- 
tained. 

Example :  "  One  says  *  give  me  a  hundred,  and  I  shall  be  twice  as  rich 
asyou,'&c.  (§  106). 

•  The  value  of  aiiy  colour,  that  is  found,  whether  expressed  by  absolute  number,  or  symbol  of 
unknown  quantity,  or  both,  and  occurring  in  another,  is  deduced  by  the  rule  of  three :  for  in- 
stance, in  example  §157,  the  value  of  ca  is  found  ni^O  pil6;  and  pi  h  lo  i    ritO;  and  ni  is 

ca9 
lo  31   ru  0.     Then  the  proportion,  ni  I  \  lo  31    ?•«  0  |  n«  20  |  ,  gives  fo  620  ru  0 ;  and  tliis,  pi  1  | 
fo4   ruO  \  pil6  \  ,  gives  lo  64   ruO.     Their  sum,    fe  684     ruO,  divided  by  9,  gives  the  value  of 
ca;  viz. /076    ru  0.     This  in  termed  utt'hdpana,  raising  or  substitution.  Crisiix. 

*  For  the  reason  of  retaining  the  symbol  of  the  unknown  ya,  in  the  fraction  expressing  its  value, 
see  note  on  §  157. 


iiSi  VIJA-GANITA.  Chapter  VI. 

Let  the  respective  capitals  he  3/al  ca  I.  Taking  a  hundred  from  the 
capital  of  the  last,  and  adding  it  to  that  of  the  first,  they  become  ya  1  ru  100 
and  ca  1  ru  100.  The  wealth  of  the  first  is  double  that  of  the  second: 
therefore  equating  it  with  twice  the  second's  capital,  a  value  oi  yavat-tdvat 
is  obtained  ca  2    ru  300      Again,  ten  being  taken  from  the  first  and  added 

ya  1 
to  the  capital  of  the  second,  there  results  ya  1    ru  10  and  ca  1    ru  10.     But 
the  second  is  become  six  times  as  rich  as  the  first:  wherefore  making  the 
second  equal  to  the  sextuple  of  the  first,  a  value  of  yavat-tavat  is  obtained 
ca  1    ru  70.     With  these  reduced  to  a  common  denomination  and  dropping 

yaS 
the  denominator,  an  equation  is  formed  ;  from  which,  as  being  one  contain- 
ing a  single  colour  (or  character  of  unknown  quantity),  the  value  of  ca 
comes  out  by  the  foregoing  analysis  (Ch.  4) ;  viz.  170.'  With  which  sub- 
stituting for  ca,  in  the  two  values  of  ydvat-tavat,  and  adding  it  to  the  ab- 
solute number,  and  dividing  by  the  appertinent  denominator,  the  value  of 
ydvat-tdvat  is  found,  40. 

157-  Example  :  The  horses  belonging  to  these  four  persons  respectively 
are  five,  three,  six  and  eight ;  the  camels  appertaining  to  them  are  two, 
seven,  four  and  one ;  their  mules  are  eight,  two,  one  and  three ;  and  tlie 
oxen  owned  by  them  are  seven,  one,  two  and  one.  All  are  equally  rich. 
Tell  me  severally,  friend,  the  rates  of  the  prices  of  horses  and  the  rest. 

Here  put  ydvat-td'cat,  &c.  for  the  prices  of  the  horses  and  the  rest.  The 
number  of  horses  and  cattle,  being  multiplied  by  those  rates,  the  capitals  of 
the  four  persons  become  ya  5     ca  Q     ni  S    pi  7      These  are  equal.     From 

ya  3  ca  7  ni  2,  pi  I 
ya  6  ca  4!  ni  1  piQ 
ya  8     ca  I     ni  3    pi  1 

the  equation  of  the  first  and  second,  the  value  of  ydvat-tdvat  is  obtained 
ca  5    ni  6   pi  6     From  that  of  the  second  and  third,  it  is  ca  3    ni  1    pi  1 

ya  ^  ya3 

In  Hke  manner,  from  that  of  the  third  and  fourth,  it  is  ca  3    ni2    pi  1.* 

yaZ 

'  The  commentator,  Crishn'a,  quotes  from  liis  preceptor,  Vishnu  Chandra,  a  rule  for  ex- 
amples of  this  nature;  abridged,  as  he  observes,  from  the  algebraic  solution. 

*  In  these  fractional  values  of  ya  deduced  from  the  preceding  equations,  by  equal  subtraction 


I 


MULTILITERAL   EQUATIONS.  233 

Reducing  these'  to  a  common  denomination,-  and  dropping  the  denomi- 
nator, the  vakie  o?  cdlaca  is  found  from  the  equation  of  the  first  and  second, 
«i  20   pi  \6 ;   and  from  that  of  the  second  and  third,  ni  8    pi  5.     From  an 

ca  9  '  cfl  3 

equation  of  these  two  reduced  to  a  common  denomination,  the  value  of 
nilaca  is  had  piSl.      This  being  "last"  value  (§  154)  the  investigation  of 

«i  4 
the  pulverizer  gives,  (as  there  is  no  additive ;')  multiplier  0,  or,  with  the 
addition  [of  its  divisor*]  lo  4  ru  0.  It  is  the  value  of  pitaca.  Also,  (for 
the  same  reason)  the  quotient  0,'  with  the  addition  [of  its  divisor*] 
/o31  ru  0.  It  is  the  value  of  nilaca.  Substituting  for  ni  and  pi  by 
their  respective  values  in  that  of  ca,  adding  them  together,  and  di- 
viding by  the  appertinent  denominator,  the  value  of  cdlaca  is  obtained 
lo  76  ru  0.  Substituting  for  ca  and  the  rest  by  their  own  values  in  that 
of  7/dvat-tdvat,  adding  them  together,  and  dividing  by  the  appropriate  de- 
nominator, the  vahie  of  ydvat-tdvaf  comes  out  lo85  ruO.  Then,  lohitaca 
being  replaced  by  unity  arbitrarily  assumed,  the  values  of  ydvat-tdvat 
and  the  rest  are  found,  85,  76,  31,  4.  Or  putting  two  for  it,  they  arc 
170,  152,  62,  8.  Or,  supposing  three,  they  are  255,  228,  93,  12.  Thus, 
by  virtue  of  suppositions,  an  infinity  of  answers  may  be  obtained. 

158 — 159.     Example  by  ancient  authors  :'     Five  doves  are  to  be  had  for 
three  drammas ;  seven  cranes,*  for  five;  nine  geese,  for  seven;  and  three 

and  then  by  proportion,  yal  \caS  ni  6   pi6  \  i/al  and  i/a3  \  caS   nil  pi'l  \  yal  also  i/a  2  I 
caS    ni2    pi  I  \  ya  1,   tlie  syllable  j/a  is  inserted  in  the  denominator  to  indicate  that  the  value  is 
olya;  not  to  include  it  as  a  factor  of  the  denominator:  for  the  first  and  third  terms  containing  it 
were  reduced  by  it  as  a  common  divisor;  and,   if  that  were  not  done,  the  numerator  would  be  a 
multiple  of  it.  Chishn. 

'  Olher  values  of  i/a  might  be  found  by  combining  the  first  and  third  ;  first  and  fourth;  and 
second  and  fourth.     But  that  is  not  done,  as  there  is  no  occasion,  Crishn. 

The  foregoing  operations  to  find  the  value  of  the  first  colour  were  in  fulfilment  of  the  rule 
4  153.    The  work  now  proceeds  to  the  finding  of  the  values  of  the  rest  by  §  ]54. 

^  See  §  63. 

♦  See  §  64. 

'  -^dya,  original  or  early  writers.  The  commentators  do  not  here  specify  them;  nor  hint 
whence  the  quotation  comes.  Su'ryada'sa  only  says  "  certain  writers;"  and  observes,  that  it  is  a 
well  known  instance.     The  rest  are  silent. 

*  Surasa,  the  Siberian  crane:  Ardea  Siberica. 

H   H 


234  VI'JA-GAN'ITA.  Chapter  VI. 

peacocks,  for  nine :  bring  a  hundred  of  these  birds  for  a  hundred  drammas, 
for  the  prince's  gratification. 

In  this  case,  putting  y6vat-t&vat,  &c.  for  the  prices  of  the  doves,  &c.  find 
the  number  of  birds  of  each  kind  by  proportion ;  and  make  the  equation 
with  a  hundred.  Or  else  multiply  the  rates  three,  five,  &c.  and  the  number 
of  birds  five,  seven,  &c.  hy  y&xiat-tuvat,  and  severally  make  an  equation  with 
a  hundred.'  Thus,  ya  3,  ca  5,  ni  7,  pi  9,  being  the  prices,  make  their 
sum  equal  to  a  hundred;  and  the  value  of  ydvat-tdvat  is  found 
ca5  iiij  pi  9  ru  100.     Again,  making  the  h'nxhyaS,  ca7,  ni9,  pi  3,  equal 

to  a  hundred,  the  value  of  ydvat-tdvat  h  obtained  caj    ni9   pi  3    ru  100. 

ya5 
From  the  equation  of  these,  reduced  to  a  common  denomination,  and  drop- 
ping the  denominator,  the  value  of  cdlaca  is  had  ni  2    pi  9    ru  50.    The 

ca  1 
dividend  here  contains  two  colours;  therefore  the  value  of  pitaca  is  arbitra- 
rily assumed  four.    With  this  substituting  fox  pitaca,  there  results  ni  2   rw  14. 

ca  1 
Hence  by  investigation  of  the  pulverizer,  the  quotient  and  multiplier,  with 
their  additives   [multiples  of  their  divisors],    are   /o  2    r«  14  value  of  ca 

lo  1    ru   0    —     of  ni 

loO    ru   4    —      of  pi 

Substituting  for  cdlaca  and  the  rest,  by  these  their  values,  in  the  value  of 

*  In  the  argument  of  proportion  the  sura  of  the  rates  as  well  as  of  the  birds  is  twenty-four :  and 
the  requisition  is  a  hundred.  From  some  multiple  of  the  argument  or  money,  the  number  of  birds 
is  to  be  found.  If  the  birds  be  found  from  the  argument  mulliplied  by  an  equal  factor,  the  sum 
of  both  will  not  be  a  hundred  :  for  the  sum  of  the  drammas,  which  are  the  arguments,  multiplied  by 
four,  is  ninety-six  ;  and  so  is  that  of  the  birds  multiplied  by  the  same  ;  and  the  sum,  multiplied  by 
five,  is  a  hundred  end  twenty.  If  indeed  they  be  multiplied  by  a  proportional  factor,  namely 
twenty-five  sixths,  the  sum  will  no  doubt  be  a  hundred  ;  but  the  birds  will  not  be  entire.  There- 
fore unequal  factors  must  be  used:  a  different  one  for  the  price  of  the  doves ;  and  another  for  that 
of  the  cranes ;  one  for  the  rate  of  the  geese ;  and  another  for  that  of  the  peacocks.  Those  &ctors 
are  unknown  ;  and  therefore  ydvat-that,  &c.  are  put  for  them.  The  rates  multiplied  are  the 
prices  paid.  Then,  as  three  drammas  are  to  five  doves,  so  is  the  price  ya  3  to  the  number  of  doves 
bought,  ya  5.     In  like  manner  the  numbers  of  the  other  birds  are  found  by  proportion. 

Or  put  y&vat-tivat,  &c.  for  the  prices  paid,  which  are  unknown :  and  thence  compute  the 
number  of  the  birds  of  each  kind  by  proportion:  \\z.ya§  caf  ni  ^  p'^  i-  The  solution  will  be 
the  same,  with  this  difference,  however,  that  the  sum  of  the  birds  must  be  taken  by  reduction  of 
the  fractions  to  a  common  denomination.  Cri'shn. 


MULTILITERAL    EQUATIONS.  235 

yavat-tdvat,  and  dividing  by  its  denominator,  the  value  of  ycecat-tkoat  is 
brought  out  lo  1  ru  2.  Substituting  for  lohitaca  with  three  arbitrarily 
assumed  for  it,  the  values  of  yavat-tavat  and  the  rest  come  out  1,  8, 
3,  4.  With  these  "  raising"  the  birds  and  their  •  prices,  the  answer  is 
Prices  3  40  21  ^Q  Or,  by  putting  four,  the  values  are  2,  6,  4,  4 ;  and 
Birds    5     56     27     12 

the  answer  is  Prices     6     30     28     36     Or,  by  supposition  of  five,  the  values 
Birds     10     42     36     12 

are  3,  4,  5,  4 ;  and  the  answer   Prices    9    20     35     56 

Birds     15     28     45     12 

Thus,  by  means  of  suppositions,  a  multitude  of  answers  may  be  obtained. 

160.  Example:*  What  number  is  it,  which,  being  divided  by  six,  has 
five  for  a  remainder ;  or  divided  by  five,  has  a  residue  of  four ;  or  divided 
by  four,  has  a  remainder  of  three ;  or  divided  by  three,  leaves  two  ? 

Let  the  number  heya  1.  This,  divided  by  six,  has  five  for  a  remainder  : 
division  by  six  being  therefore  made,  the  quotient  is  ca.  The  divisor,  mul- 
tiplied by  ca,  with  its  remainder  five  added  to  it,  is  equal  to  ya.  From  this 
equation  the  value  of  ya  is  obtained  ca  6  ru  5.     In  like  manner,  ni,  &c.  are 

quotients  answering  to  the  divisors  five  and  so  forth ;  and  values  of  ya  are 
thence  obtained :   «/5   rM4     pi4>  ru3     lo  3   ruQ.      From  the  equation  of 

yal  ya\  ya  I 

the  first  and  second  of  these  values,  a  value  of  ca  is  deduced,  ni  5  rul  ; 

ca  6 
from  the  equation  of  the  second  and  third,  a  value  of  ni,  viz.  pi4<  ru  I  ; 

ni5 
and  from  that  of  the  third  and  fourth,   a  value  of  pi,  namely  lo3    rul. 

pi4< 
Hence,'^    by    investigation    of   the    pulverizer,   values   of  lo  and  pi   are 
brought  out;   which,  with  the  additives  [derived  from  the  divisors'],   are 

ha  3    ru  ^    of  d'     Substituting  for  pi  by  that  value,  in  the  value  o 

•  To  illustrate  the  rule  for  exterminating  a  fraction.    §  156.  Cri'shn. 

»  It  is  "  last"  value :  wherefore  investigation  of  the  multiplier  takes  place.    §  154.      CRfsBN. 
'  See  %  64. 

H  H  2 


236  VI'JA-G  ANITA.  Chapter  VI. 

ni,  this  becomes  Art  19    ru7  :*   and  here  dividing  it  by  its  denominator,  the 

value  of  mI  comes  out  a  fraction.*  Removing  then  the  fraction  by  investiga- 
tion of  the  pulverizer,  the  niultiphcr,  with  its  additive  [borrowed  from  the 
divisor,]  as  found  by  that  method,  is  srceS  ruA.  It  is  the  vahie  of  /la. 
Substituting  with  this  for  ha  in  the  values  of  lo  and  pi,^    they  become 

swe  }5  rw  14  value  of />^  Now  substituting  for  pi,  with  this  value,  in  the 
szve20  ru  19     —    of  lo 

value  of  «/,*  and  dividing  by  its  denominator,  the  value  of  w?  is  brought  out, 
without  a  fraction,  srve  12  ru  11.  Substituting  for  7ii  with  this  value,  in 
the  value  of  ca,  and  dividing  by  the  denominator,  the  value  of  ca  is  obtained 
swe  10  ru  9.  Substituting  for  ca  and  the  rest,  by  these  values  in  the  several 
values  of  ^fl,  it  comes  out  *a'e  60   ru59J 

Or  [putting  ya  1  for  the  quantity]  divided  by  six  and  having  five  for  a  re- 
mainder (§  160),  the  quantity  is  ca6  ru5,  as  before.  This,  divided  by  five, 
has  a  residue  of  four  (§  160)  :  put  ni  for  the  quotient;  and,  by  the  equation 
with  the  divisor  multiplied  by  that  quotient  and  added  to  the  residue 
(ni  5   ru  4),  there  results  ni  5    ru  I    the  value  of  ca  in  a  fractional  expres- 

ca  6 
sion.  By  investigation  of  the  pulverizer,  that  value,  in  an  expression  not 
fractional,  becomes  pi  5  ru  4.  Substituting  for  ca  with  this,  in  the  original 
value,  ca6  ru  5,  it  is  pi  30  ru  29-  This  again,  divided  by  four,  has  a  re- 
mainder of  three  (§  1 60)  :  an  equation  then  being  made  as  before,  there  re- 
sults lo  4    ru  26.     Here  also,  by  investigation  of  the  pulverizer,  the  value 

pi  30 
of  pi  is  converted  into  ha  2    rul.     Whence,  substituting  with  it,  in  the 
expression  pi  30    ru  29,  the  quantity  is  found  ha  60   ru  59.     This  again, 

*  By  the  rule  of  three  terms  :  pi  I  \  ha  3  ru  2  \  pi  4  {  ha  12  ru  8.  This  value  of  pi  4,  with 
ml,  makes //a  12   ruj.  Cri'shk. 

*  Division  by  the  denominator  does  not  succeed  exactly.  Su'r. 
^  Being  the  two  "  last"  values.                                                                                          CRfsHN. 

*  This  is  inverse  substitution,  commencing  from  the  "  first"  or  preceding  (§  156),  which  is  her^ 
7ii.  Crishn. 

'  It  comes  out  the  same  in  all  the  expressions  of  the  value  of  ya :  and  putting  nought  for  sjve 
(and  thus  exterminating  the  unknown  term)  the  conditions  of  the  question  are  all  answered  with 
the  remaining  number. — Su'r.  And  the  quotients  or  values  of  co,  &c.  are  9)  I'l  14,  1.9.  By  the 
supposition  of  one  for  swe,  the  number  is  119  J  and  the  quotients  are  19,  23,  29,  and  39.     Crishh. 


MULTILITERAL    EQUATIONS.  237 

divided  by  three,  leaves  two  (§  160)  :  and  the  quantity  here  comes  out  the 
same.  By  substituting  nought,  one,  two,  &c.  a  multipUcity  of  answers 
may  be  obtained. 

161.  Example:  "What  numbers,  being  multiplied  respectively  by  five, 
seven,  and  nine,  and  divided  by  twenty,  have  remainders  increashig  in  pro- 
gression by  the  common  difference  one,  and  quotients  equal  to  the  re- 
mainders. 

In  this  case  put  the  residues  yal,  yal  ru  \,  ya\  ru  2.  They  are  the 
quotients  also.  Let  the  first  number  be  ca  1.  From  this  multiplied  by  five, 
subtracting  the  divisor  taken  into  the  quotient,  the  remainder  is  ca  5  ya  20. 
Making  this  equal  to  ya  1,  a  value  oi yavat-tdvat  is  obtained  ca    5.      Let 

yaJl 
the  second  number  be  put  ni  1.     From  this  multiplied  by  seven,  subtracting 
the  divisor  taken  into  ya  added  to  one,  the  result  is  n't  7   ya  20    rti  20;  and 
making  this  equal  to  ya  1    ru  I,  a.  value  of  ydvat-tdvat  is  had  ni7    rti  9,\. 

ya'2l 
Let  the  third  number  be  pi  1.     From  this  multiplied  by  nine,  subtracting  the 
divisor  taken  into  ya  added  to  two,  the  residue  is  pi  9   ya  20    ru  40;  and 
making  this  equal  to  ya  1   rwS,  a  value  of  ydvat-tdvat  is  found  pi  9  ;7<4S. 

_y«  21 
From  the  equation  of  the  first  and  second  of  these,  the  value  of  cdlaca  is 
«i  7    7'm21  ;  and  from  that  of  the  second  and  third,  the  value  of  n'dacaip 
ca  5  rt 

pi  9    ru  21.      This  being  "  last"  value,  the  investigation  of  the  pulverizer 

nil 
takes  place  :  and  quotient  and  multiplier,  with  additives  [derived  from  their 
divisors],  arc  by  that  method  found,  lo  9  ''«  6  value  of  ni     Here  the  additive 

lo7  ru7     —    of  pi 
is  designated  lohitaca;^  and  the  expressions  in  their  order,  arc  values  of 
nilaca  axvX  pitaca.     Substituting  for  ni  by  this  value,  in  that  of  c«,  and  di- 
viding by  its  denominator,  the  value  of  ca  comes  out  fractional  lo63    ru2l. 

ca5 
To  make  it  integer  by  investigation  of  the  pulverizer,   reduce  the  divi- 

'  The  commentator  Su'rtada'sa  pursues  the  operation,  without  introduction  of  this  symbol 
of  an  unknown  :  remarking,  that  it  would  serve  to  embarrass  and  mislead  the  student. 


J38  VI'JA-GAN'ITA.  Chapter  VI. 

dend  and  additive  to  their  least  terms  by  the  common  measure  twenty-one 

[§58],  and  the  values  calaca  and  lohitaca  are  found  ha  63    ru  42  value  of  ca 

ha   5    ru   3    —      of  /o 
Substituting  for  lohitaca  by  its  value,  in  the  values  of  n'llaca  and  pitaca, 

these  are  brought  out  ha  45    ru  33  value  of  ni     Again,  with  these  values, 

ha  35    rw  28     —    of  pi 

ha  53    ru  42  for  ca  substituting  for  calaca  and  the  rest  in  the  values  o^ y&vat- 
ha  45    ru  33  for  ni 
ha  35    rM28  fov  pi 

t6vat,  and  dividing  by  the  appertinent  denominators,  the  value  ofya  is  ob- 
tained ha  15  ru  10.  Here,  as  the  quotient  is  equal  to  the  residue,  and  the 
residue  cannot  exceed  the  divisor,  substitute  nought  only'  for  haritaca,  and 
the  quotients  are  found  10,  11,  12.  Deducing  ca/aca  and  the  rest  from 
their  values,  the  quantities  are  brought  out  in  distinct  numbers,  42,  33,  28. 

162.  Example :  What  number,  being  divided  by  two,  has  one  for  re- 
mainder ;  and,  divided  by  three,  has  two ;  and,  divided  by  five,  has  three : 
and  the  quotients  also,  like  itself? 

Let  the  number  be  put  ya  1.  This,  divided  by  two,  leaves  one;  and  the 
quotient  also,  divided  by  two,  has  a  remainder  of  one.  Let  the  quotient  be 
ca2  ru\.  The  divisor  multiplied  by  this,  with  addition  of  the  residue, 
being  equal  to  ya\,  the  value  oi  yavat-tavat  is  obtained,  cfl4  ruS.  It 
answers  one  of  the  conditions.  Again,  the  number,  being  divided  by  three, 
has  a  residue  of  two :  and  so  has  the  quotient.  Put  ni  3  ru  2.  This,  mul- 
tiplied by  the  divisor,  and  added  to  the  residue,  is  «?  9  ru%;  which  is  equal 
to  cfl  4  ruS;  whence  the  value  of  ca  is  fractional.  Cleared  of  the  fraction 
by  means  of  the  pulverizer,  it  becomes  pi  9  ru  8 ;  with  which,  substituting 
for  ca,  the  number  is  found  pi  36  ru  35.  This  answers  two  of  the  condi- 
tions. Again,  the  same  number,  divided  by  five,  has  a  remainder  of  three  ; 
and  so  has  the  quotient.  Put/o5  ru3.  This,  multiplied  by  the  divisor, 
and  added  to  the  residue,  is  /o25  ru  18.  Making  it  equal  to  pi  36  ru  35, 
the  value  of  pi  is  fractional.  Clearing  it  of  the  fraction  by  the  pulverizer, 
the  result  is  ha  35  ru  3.  Substituting  with  this  for  pi,  the  number  is  found 
ha  900    rMl43.     Substituting  for  ha  with  nought,  the  number  comes  out 

•  Supposing  unity,  the  quotients  would  come  out  25,  26  and  27-— Ram.    And  would  exceed 
the  divisor  20. 


MULTILITERAL    EQUATIONS.  239 

143.^     Division  being  made  conformably  with  the  conditions  of  the  problem, 
the  quotients  are  71,  47  and  28;  and  by  these  the  conditions  are  fulfilled. 

163.  Example :  Say  what  are  the  numbers,  except  six  and  eight,* 
which,  being  divided  by  five  and  six  respectively,  have  one  and  two  for  re- 
mainder;  and  the  difference  of  which,  divided  by  three,  has  a  residue  of  two; 
and  their  sum,  divided  by  nine,  leaves  a  remainder  of  five  ;  and  their  pro- 
duct, divided  by  seven,  leaves  six?  if  thou  can  overcome  conceited  proficients 
in  the  investigation  of  the  pulverizer,  as  a  lion  fastens  on  the  frontal  globes 
of  an  elephant. 

In  this  case,  the  two  numbers,  which  being  divided  by  five  and  six,  leave 
one  and  two  respectively,  are  put  ya5  ru  I  and  i/a  6  ru  2.  The  difference 
of  these,  divided  by  three,  gives  a  residue  of  two.  Put  ca  for  the  quotient ; 
and  let  the  divisor  multiplied  by  that  added  to  the  residue  (ca  3  ru  I)  be 
equated  with  the  difference  i/a  I  ru  I.  The  value  of  ya  is  obtained  ca  3 
ru  1.  The  two  numbers  deduced  from  substitution  of  this  value  are  ca  15 
ru  6  and  ca  1 8  ru  8.  Again,  the  sum  of  these,  divided  by  nine,  leaves  five. 
Put  ni  for  the  quotient ;  and  let  the  divisor,  multiplied  by  that  and  added 
to  the  remainder  (niQ  ru  9)  be  equated  with  the  sum  ca33  rw  14.  The 
value  of  ca  is  had  nig    ru9;  and  is  a  fraction.     Rendering  it  integer  by 

ca33 
the  pulverizer,  it  becomes  pi  3  ru  0.  From  which  the  two  quantities,  de- 
duced by  substitution,  are  pi  45  ru  6  and  pi  54  ru  8.  Again,  proceeding 
to  the  product  of  these,  as  it  rises  to  a  quadratic,  the  operation  is  a  grand 
one.'  Wherefore,  substituting  with  unity  for  pi,  the  first  quantity  is  made 
an  absolute  number,  51.  Again,  the  product  of  these,  abraded*  by  seven, 
yields  pi  3  ru  1.  Put  lo  for  the  quotient  of  this  dividend  by  seven  to  leave 
six.  The  divisor  multiplied  by  that  quotient  and  added  to  the  residue 
[lo  7  ru6\  is  equal  to  the  abraded  product  {pi  3    ru  2).     Thence,  by  inves- 

'  This  sentence,  which  is  wanting  in  two  of  the  collated  copies,  is  found  in  the  margin  of  one, 
and  in  the  text  of  that  which  is  accompanied  by  the  gloss  of  Ra'ma-Cbishn'a  ;  where  alone  the 
subsequent  sentence  occurs.     Both  are  repeated  in  his  commentary. 

*  These,  furnishing  too  obvious  an  answer  to  the  question,  (for  they  fulfil  all  its  conditions,)  are 
excepted.  Crishn. 

'  It  is  vain ;  for  the  equation  rises  to  cubic  and  biquadratic.  Sea. 

♦  See  %  56. 


J40  V  I'J  A-  G  A  N'l T  A.  Chapter  VI. 

tigation  of  a  pulverizer  as  before,  the  value  of  pi  is  found  ha  7  ruG.^  The 
number  deduced  by  substitution  of  this  comes  out  Iia  378  7-u  332.  The 
additive  of  the  former  number  (pi  45)  multiplied  by  this  {ha  7)  is  its  present 
additive  (ha  315):  and  thus  the  first  number  or  quantity  with  its  additive  is 
brought  out  Afl  3 1 5    ru  51. 

Or  else  putting  an  absolute  number  for  the  firsts  the  second  is  to  be 
sought.* 

164.  Example:  What  number  is  it  which  multiplied  severally  by  nine 
and  seven,  and  divided  by  thirty,  yields  remainders,  the  sum  of  which,  added 
to  the  sum  of  the  quotients,  is  twenty-six  ? 

As  the  divisor  is  the  same,  and  the  sum  of  the  remainders  and  quotients 
is  given,  the  sum  of  the  multiplicators  is  for  shortness  made  the  multiplier; 
and  the  number  is  putya  1.  This,  multiplied  by  the  sum  of  the  multipli- 
cators, hi/a  16.  Put  ca  for  the  sum  of  the  quotients  of  the  division  by 
thirty.  Subtracting  the  divisor  taken  into  that  (ca  30)  from  the  immber 
multiplied  by  the  [sum  of  the]  multiplicators  (j/a  16);  and  equating  the  dif- 
ference added  to  the  quotient,  with  twenty-six,*  the  value  of  ya  found  by 
the  pulverizer  is  ni  29  ru  27.  As  the  sum  of  the  remainders  and  quotients 
is  restricted,  the  additive  is  not  to  be  applied.  Substituting  therefore  with 
nought  for  ni,  the  value  of  i/a  is  27:  and  this  is  the  number  sought. 

1 65.  Example :  What  number  being  severally  multiplied  by  three,  seven, 
and  nine,  and  divided  by  thirty,  the  sum  of  the  remainders  too  being  divided 
by  thirty,  the  residue  is  eleven? 

In  this  case  also,  the  sum  of  the  multiplicators  is  made  the  multiplier,  as 
before  (§  164):  viz.  19.  The  number  is  put  i/a  1.  The  quotient  ca  I. 
Subtracting  the  divisor  multiplied  by  this  from  the  number  taken  into  the 

'  Equation  pi  3  loO  ruZ     Whence,  by  subtraction,  lo7   ru-i  :  and,  clearing  the  fraction  by 
pis    lo7    ru 6  ~pi3 

means   of    the  pulverizer,    the  quotient  and    multiplier  are  6  and  2.      Whence   the  values 

ia7    ru6  of  pi 

ha  3    ru2  of  lo  Si/a.  and  Ram. 

*  Putting  6,  it  is  ha  126   ru  8.     Or  putting  36,  it  is  ha  126   ru  104,  Ram, 

*  2/a  \6    ca  29     ru   0 

3/a  0    ca   0    ru  26  Sua.  and  Ram. 


MULTILITERAL    EQUATION.  241 

multiplicator,  the  remainder  is  t/a  19  ca  30.  The  sum  of  the  remainders, 
abraded  by  thirty,  leaves  a  residue  of  eleven.  The  second  condition  there- 
fore being  comprehended  in  the  first,  this  is  equal  to  eleven;  and  from  such 
equation,  proceeding  as  before,'  the  number  comes  out  ni  30    ru  29> 

165.  Example:  What  number  being  multiplied  by  twenty-three,  and 
severally  divided  by  sixty  and  eighty,  the  sum  of  the  remainders  is  a  hun- 
dred.''   Say  quickly,  algebraist. 

167.  Maxim:  If  more  than  one  colour  represent,  in  a  dividend,  quo- 
tients of  a  numerator,  an  arbitrary  value  is  not  to  be  assumed,  lest  the  solution 
fail.* 

Therefore  it  must  be  treated  otherwise.     In  this  instance  the  solutionis  to 

be  managed  by  distributing  the  sum  of  the  residues,  so  as  these  may  be  less 

tlian  their  divisors  and  nothing  be  imperfect.     Accordingly  the  remainders 

are  assumed  40  and  60.     The  number  is  put  i/a  1.     This,   multiplied  by 

twenty-three  and  divided  by  sixty,  gives  a  quotient:  for  which  put  ca.     The 

divisor  taken  into  that  and  added  to  the  remainder  being  equated  with  this 

term  i/fl  23,  a  value  of  ya  is  obtained,  ca  60     ru  40.    In  like  manner,  ano- 

ya  23 

ther  value  is  had  ni  80   ru  60.     From  the  equation  of  these,  the  values  of  ca 

ya9.3 

and  ni  are  found  by  the  pulverizer,  pi  4     ru  3  value  of  ca      Substituting 

pi  3     ru  2  of  fii 

'  Equation  j/a  19     ca  30     ru    0     Whence  value  of  j/a,     ca  30     rail     By  the  pulverizer,  the 
ya   0     ca    0     ru  11  'i/alg 

multiplier  and  quotient  are  18  and  13.  Making  these  the  values,  and  changing  the  letter,  the 
number  is  found  ni  30   ru  29.  Sua. 

*  Putting  ya  1   for   the  number,  and    ca  1   and   ni    1    for  the   quotients,   the   value  of  ya  is 
ca  6o     ni  80     ru  100,  or  reduced  to  least  terms  ca  30     ni  40     ru  50     This  is  to  be  cleared  of 

ya  id  ya  23 

the  fraction :  and,  by  the  rule  (§  155),  as  there  is  more  than  one  colour,  either  ca  or  ni  may  be  put 
arbitrarily  any  number.  But  they  are  quotients  of  the  same  dividend  or  numerator  by  the  divisors 
60  and  80.  If  an  absolute  number  be  put  for  ca  the  quotient  of  60,  then  ni,  the  quotient  of  80,  is 
absolute  too;  being  a  quarter  less.  So  likewise,  if  any  number  be  put  for  ni,  the  quotient  of  80, 
then  ca,  the  quotient  of  60,  is  absolute  also,  being  a  third  more.  Such  being  the  case,  the  solution 
woulil  not  conform  to  the  sum  of  the  remainders  given  at  a  hundred.  Nor  would  the  answer  agree 
with  the  question;  if  the  assumption  be  arbitrarily  made.  Cuishn.  and  Ram. 

I  I 


242  VI'JA-G  ANITA.  Chapter  VI. 

with  these,  the  value  of  ca  is  brought  out,  a  fraction,  pi  240     ru  220 .  Clear- 

ya  23 
ing  it  of  the  fraction  by  the  pulverizer,  it  becomes  lo  240   7'u  20.'     Or  let 
the  remainders  be  put  30  and  70.     From  these  the  number  is  deduced  lo  240 
ru  90.^    In  like  manner,  a  multiplicity  of  answers  may  be  found. 

168.  Example:  Say  quickly  what  is  the  number,  which,  added  to  the 
quotient  by  thirteen  of  its  multiple  by  five,  becomes  thirty? 

Put  ya  1  for  the  number.  This,  multiplied  by  five  and  divided  by  thir- 
teen, gives  a  quotient:  for  which  put  ca.  The  quotient  and  original  num- 
ber, added  together,  yal  ca  1,  are  equal  to  thirty.  But  this  equation  does 
not  answer.  For  there  is  no  ground  of  operation,  since  neither  multiplier, 
nor  divisor,  is  apprehended.     Accordingly,  it  is  said 

169.  In  a  case  in  which  operation  is  without  ground  or  in  which  it  i$ 
restricted,  do  not  apply  the  operation  :  for  how  should  it  take  effect?' 

The  solution  therefore  is  to  be  managed  otherwise  in  this  case.  If  then 
the  number  be  put  equal  to  the  divisor  in  the  instance,  viz.  13,  the  propor- 
tion "  as  this  sum  of  number  and  quotient,  1 8,  is  to  the  quotient  5,  so  is  30 
to  what?"  brings  out  the  quotient  "^ ;  and  subtracting  this  from  thirty,  the 
remainder  is  the  number  sought,  which  thus  is  found  V- 

170.  Example  instanced  by  ancient  authors:  a  stanza  and  a  half.  Three 
traders,  having  six,  eight,  and  a  hundred,  for  their  capitals  respectively, 
bought  leaves  of  betle*  at  an  uniform  rate;  and  resold  [a  part]  so;  and  dis- 
posed of  the  remainder  at  one  for  five  panas;  and  thus  became  equally  rich. 
What  was  [the  rate  of]  their  purchase?  and  what  was  [that  of]  their  sale? 

'  Substituting  nought  for  16,  the  conditions  are  answered.  Su'r. 

*  Put  ya  1  for  the  number;  and  ca  4  and  ca  3  for  the  quotients.  Subtract  the  quotient  taken 
into  its  divisor,  from  the  dividend,  the  remainders  are  found  j/a  23     co  240    They  are  alike;  and, 

ya  23     ca  240 

as  their  sum  is  a  hundred,  each  is  equal  lo  fifty.     From  this  equation,  the  values  of  ya  and  ca  arc 

brought  out,  by  means  of  the  pulverizer,  n't  240     ru  19O  value  oi  ya. 

ni    22     ru    18  value  of  cff.  Crishn. 

^  Very  obscure :  butnot  rendered  more  intelligible  by  the  commentators. 

♦  Ra'macrishn A  reads  and  interprets  data  leaves  of  (N6gaxall'0  piper  betle.  Another  reading 
it  jihala,  fruit. 


MULTILITERAL    EQUATION.  MS' 

Put  7/fl  1  for  the  [rate  of]  purchase;  and  let  the  [rate  of]  sale  be  assumed  a 
hundred  and  ten.  Tlie  purchase,  multiplied  by  six  and  divided  by  the  sale, 
gives  a  quotient;  for  which  put  ca  1.  Subtracting  the  divisor  multiplied  by 
this,  from  the  quantity  multiplied  by  six,  the  remainder  is  ya  6  ca  110. 
This,  multiplied  by  five,  and  added  to  the  quotient,  gives  the  number  of 
pafias  belonging  to  the  first  trader.  In  like  manner  the  money  of  the  second 
and  of  the  third  is  to  be  found.  Here  the  quotient  is  deduced  by  the  pro- 
portion '  as  six  is  to  ca,  so  is  eight  (or  a  hundred)  to  what  r'  The  quotient  of 
eight  comes  out  ca  f;  and  that  of  a  hundred,  ca  ^j".  Subtracting  the  divi- 
sor taken  into  the  quotient,  from  the  dividend,  the  remainder,  multiplied  by 
five  and  added  to  the  quotient,  gives  the  paiias  appertaining  to  the  second, 
ya  ^  ca  ^^  In  like  manner  the  third's  money  is  found,  ya  ^p-  ca  ^4^". 
These  are  all  equal.  Reducing  them  to  a  common  denomination,  and  drop- 
ping the  denominator,  and  taking  the  equation  of  the  first  and  second,  and 
that  of  the  second  and  third,  the  value  of  ya  comes  out,  alike  [both  ways], 
ca  549 :  And,  by  the  pulverizer,  it  is  found  n'l  549  ru  0.  Substituting 
ya  30 
with  unity  for  7ii,  the  rate  of  purchase  is  brought  out,  549.* 

This,  which  is  instanced  by  ancient  writers  as  an  example  of  a  solution 
resting  on  uuconfined  ground,  has  been  by  some  means  reduced  to  equation ; 

'  Equation  of  the  1st  and  2d  ya  30     ca  549,  reduced  to  a  common  denomination  j^u  90    ca  l647 

„(,  igo  eg  gi'on  ya  120  ca2l96 

Wiience  value  of  ya    ca  549. 
yaSO 
Equation  of  2d  and  3d,  ya    120    ca    2196    Whence  value  of  ya  ca  23254  and,  abridging  by 
ya  1500    ca  27450  ya  1380 

46,  ca  549. 
ya30 

Equation  of  1st  and  3(1,  ya      90     ca    l647     Whence  value  of  ya  ca  25803  and,  abridging  by 
ya  1500     ca  27450  ya  1410 

47,  ca  549     Proceeding  by  the  pulverizer,  the  quotient  and  multiplier,  briefly  found  under  the 

ya  30 

rule  (§  63),  are  nl  549  And  the  value  of  ya  the  colour  of  the  divisor,  comes  out  ni  549   ru  0 ; 

ni      0    ru  0 

and  that  of  ca,  the  colour  of  the  dividend,  ni  30  ru  0.     At  549  betle  leaves  for  a  paiia,  six  bring 

3294;  eight,  4392  ;  and  a  hundred,  54900:  which  sold  at  the  rate  of  110,  fetch  29,  39  and  499; 

leaving  remainders  104,  102  and  10;  and  these  at  the  rate  of  one  for  five,  bring  520,  510  and  50. 

Added  together,  in  their  order,  they  make  the  amount  of  the  sale  549.  Ram. 

I  I  2 


244  VI'JA-G  ANITA.  ChapteeVI. 

and  such  a  supposition  introduced,  as  has  brought  out  a  result  in  an  unre- 
stricted case  as  in  a  restricted  one.  In  the  like  suppositions,  when  the  opera- 
tion, owing  to  restriction,  disappoints ;  the  answer  must  by  the  intelligent 
be  elicited  by  the  exercise  of  ingenuity.     Accordingly  it  is  said, 

'  The  conditions,   a  clear   intellect,  assumption  of  unknown  quantities, 
equation,  and  the  rule  of  three,  are  means  of  operation  in  all  analysis.' 


i 


CHAPTER    VII. 


VARIETIES   OF   QUADRATICS.' 

Next,  varieties  of  the  solution  involving  extermination  of  the  middle 
term  are  propounded. 

171 — 174.  Rule  beginning  with  the  latter  half  of  the  concluding  stanza 
[in  the  preceding  rule,  §  156] :  three  and  a  half  stanzas.  Equal  subtraction* 
having  been  made,  when  the  square  and  other  terms  of  the  unknown  re- 
main, let  the  square-root  of  the  one  side  be  extracted  in  the  manner  before 
directed ;'  and  the  root  of  the  other,  by  the  method  of  the  affected  square,* 
and  then,  by  the  equation  of  the  two  roots,  the  solution  is  to  be  completed. 

173.  If  the  case  be  not  adapted  to  the  rule  of  the  affected  square,  make 
the  second  side  of  equation  equal  to  the  square  of  another  colour,  and  find 
the  value  of  the  colour,  and  so  the  value  of  the  first,  through  the  affected 
square.  By  ingenious  algebraists  many  different  ways  are  to  be  devised:  so 
as  to  render  the  case  fit  for  the  application  of  that  method. 

174.  For  their  own  elemental  sagacity  (assisted  by  various  literal  sym- 
bols) which  has  been  set  forth  by  ingenious  ancient  authors,'  for  the  in- 

*  Ma<rh]/amdharana-bAeda:  varieties  of  quadratie»  &c.  equations.     See  Cli.  5. 

'■  Sama-sod'hana,  tulya-sudd'hi,  equal  subtraction  ;  or  transposition,  with  other  preparations  of 
the  equation.     See  §  101.  Ch.  4. 

5  SeeCh.5.  §  128  and  131. 

♦■Ch.3, 

'  BRAHMEGurrA  andCHATuRVEDA.andlhereit, — Si/R,.meaningCHATUKVKDA  Pbit'hu'daca, 
VHAni  the  scholiast  of  Brahmecupta. 


24G  VI'JA-GAN'ITA.  Chapter  VII. 

struction  of  men  of  duller  intellect,  irradiating  the  darkness  of  mathematics, 
has  obtained  the  name  of  elemental  arithmetic' 

After  equal  subtraction  has  been  made,  if  a  square  of  the  unknown  with 
other  terms  remain,  then  the  square-root  of  the  one  side  of  the  equation  is  to 
be  extracted  in  the  manner  before  taught  (§  I'SS).  If  the  square  of  an  un- 
known with  unity  stand  on  the  other  side,  two  roots  are  to  be  found  for  this 
side  of  the  equation  by  the  method  of  the  affected  square  (Ch.  3).  Here  the 
number,  which  stands  with  the  square  of  the  colour,  is  (pracrUi)  the  coeffi- 
cient affecting  it.'  And  the  absolute  number  is  to  be  made  the  additive. 
In  this  manner,  the  "  least"  root  is  the  value  of  the  colour  standing  with  the 
coefficient,  and  the  "  greatest"  is  that  of  the  root  of  the  whole  square. 
Making,  therefore,  an  equation  to  the  root  of  the  first  side,  the  value  of  the 
preceding  colour  is  to  be  thence  brought  out. 

But,  if  there  be  on  one  side  of  the  equation,  the  square  of  the  unknown 
with  the  [simple]  unknown,  or  only  the  [simple]  unknown  with  absolute 
number,  or  without  it ;  such  is  not  a  case  adapted  for  the  method  of  the  af- 
fected square :  and  how  then  is  the  root  to  be  found  ?  The  text  proceeds 
to  answer  '  If  the  case  be  not  adapted,  &c.'  (§  173).  Making  it  equal  to  the 
square  of  another  colour,  the  root  of  one  side  of  the  equation  is  to  be  ex- 
tracted as  before ;  and  two  roots,  by  the  rule  of  the  affected  square,  to  be 
investigated,  of  the  other  side :  and  here  also,  the  "  least"  is  the  value  of  the 
colour  belonging  to  the  coefficient,  and  the  "greatest"  is  square-root  of  the 
side  of  the  equation.  Then  duly  making  an  equation  of  the  roots,  the  values 
of  the  colours  are  to  be  thence  found. 

If  nevertheless,  though  the  second  side  be  so  treated,  the  case  be  still  not 
adapted  to  the  rule,  the  intelligent,  devising  by  their  own  sagacity,  means 
of  bringing  it  to  the  form  to  Avhich  the  rule  is  applicable,  must  discover 
values  of  the  unknown. 

If  they  are  to  be  discovered  by  the  mere  exercise  of  sagacity,  what  occa- 
sion is  there  for  algebra?  To  this  doubt,  the  text  replies  (§  174).  Because 
sagacity  alone  is  the  paramount  elemental  analysis :  but  colours  (or  symbols) 

•  Vija-mati,  causal  sagacity  :  for  nothing  can  be  discovered,  unless  by  ingenuity  and  penetration. 
Vija-ga/iila,  causal  calculus :  from  vija,  primary  cause,  and  ganita,  computation.  SuR. 

•  The  number  Conca)  or  coefficient  is  the  pracrltti,  or  subject  aflTecting  the  colour  or  symbol 
that  is  squared.    SeeCh.  3.  under  §  75.  ' 


VARIETIES    OF    QUADRATICS.  247 

are  its  associates  ;  and  therefore  ancient  teachers,  enhghtening  mathemati- 
cians as  the  sun  irradiates  the  lotus,  have  largely  displayed  their  own  saga- 
city, associating  with  it  various  symbols :  and  that  has  now  obtained  the 
name  of  (Vija-ganita)  elemental  arithmetic.  This  indeed  has  been  suc- 
cinctly expresssed  by  a  fundamental  aphorism  in  the  Siddhanta ;^  but  has 
been  here  set  forth  at  somewhat  greater  length  for  the  instruction  of  youth. 

175 — 176.  Rule  :  When  the  square-root  of  one  side  of  the  equation  has 
been  extracted,  if  the  second  side  of  it  contain  the  square  of  an  imknown 
quantity  together  with  unity  (or  absolute  number);  in  such  case  "greatest" 
and  "  least"  roots  are  then  to  be  investigated  by  the  method  of  the  affected 
square.  Making  the  "  greatest"  of  these  two  equal  to  the  square-root  of  the 
first  side  of  the  equation,  the  value  of  the  first  colour  is  thence  to  be  found, 
in  the  manner  which  lias  l)een  taught.  The  "  least"  will  be  the  value  of  the 
colour  that  stands  with  the  coefficient.  Thus  is  the  rule  of  afitcted  square 
to  be  here  applied  by  the  intelligent. 

The  meaning  has  been  already  explained. 

177.  Example:  What  number,  being  doubled  and  added  to  six  times  its 
square,  becomes  capable  of  yielding  a  square-root?  tell  it  quickly,  alge- 
braist ! 

Put  ya  for  the  number.     Doubled,  and  added  to  six  times  its  square,  it 

becomes  j/fl  17  6  ya9,.     It  is  a  square.     Put  it  equal  to  the  square  of  ca  ;  and 

the  statement  of  equation  h  yav  6   ya9.    cavO      Equal  subtraction  being 

ya  V  0   yaO    cav  I 

made  and  the  two  sides  being  multiplied  by  six,  and  superadding  imity,  the 

square-root  of  the  first  side  found  as  before  is  ya6    ru  1.     The  roots  of  the 

second  side,  investigated  by  the  rule  of  the  afi'ected  square,  are  L  2    G  5 

or  L  20    G  49-''     Here  the  "  greatest"  of  two  roots  is  the  square-root  of  the 

second  side  of  the  equation.     From  the  equation  of  that  value  (5  or  49) 

with  the  root  of  the  first  side  ya6   ru  I,  the  value  of  ya  is  found  -f  or  8* 

'  See  quotation  from  Chapter  on  Spherics  under  §  110. 

^  Assume  the  least  root  2.  Its  square  4,  multiplied  by  the  coefficient  6,  is  24.  Added  to  1,  it 
affords  the  root  5.     Statement:     C6    L2    G5    Al     Whence,  by  composition  (§  77),  1  20  g  49. 

L2    Go    A  1  SuR.  and  Ram. 


248  VIJ'A-G  ANITA.  Chaptek  VII. 

The  "least"  of  the  pair  of  roots  (either  2  or  20)  is  the  vahie  of  ca,  the  sym- 
bol standing  with  the  coefl[icient.  The  number  sought  then  is  the  integer  8, 
or  the  fi-action  -f ;  and,  in  like  manner,  by  the  variety  of  "  least"  and 
"  greatest"  roots,  a  multiplicity  of  answers  may  be  obtained. 

178.  Example  from  ancient  authors:  The  square  of  the  sum  of  two 
numbers,  added  to  the  cube  of  their  sum,  is  equal  to  twice  the  sum  of  their 
cubes.     Tell  the  numbers,  mathematician ! 

The  quantities  are  to  be  so  put  by  the  intelligent  algebraist,  as  that  the 

solution  may  not  run  into  length.     They  are  accordingly  put  ya  \    ca\ 

zx\Aya\    cal.^     Their  sum  is  ya9..     Its  square  j/a  w  4.     Its  cube  _yfl  ^A  8. 

The  square  of  the  sum  added  to  the  cube  is  ya  gh  8    ya  v  4:.     The  cubes  of 

the   two  quantities    respectively    are   ya  gh  1     ya  v.  ca  bh  3     ca  v.  ya  bh  3 

cagh  1    cube  of  the  first;  2iaA  ya  gh  1    yav.cabh  3    cav.yabh  3    caghl 

cube  of   the  second ;    and    the  sum  of    these    is   ya  gh  2    ca  v.  yabhS; 

and   doubled,   ya  gh  4i    cav.yabh  l^.      Statement   for   equal    subtraction: 

yaghS  yav  4i  cav.yabh  0  After  equal  subtraction  made,  depressing 
yaghAs   yav  0    cav.yabh  19, 

both  sides  by  the  common  divisor  ya,  and  superadding  unity,  the  root  of  the 

first  side  of  equation  is  j/a  2    ru  \.     Roots  of  the  other  side  (cav  12    ru  1) 

are  investigated  by  the  rule  of  the  affected  square,^  and  are  L2    G/  or 

X28   G97.     "  Least"  root  is  a   value  of  ca.     Making  an  equation  of  a 

"  greatest"  root  with  ya  2    ru  1,  the  value  of  ya  is  obtained  :  viz.  3  or  48. 

Substitution  being  made  with  the  respective  values,  the  two  quantities  come 

out  1  and  5,  or  20  and  76,  and  so  forth. 

179 — 180.  Rule:  a  stanza  and  a  half.  Depressing  the  second  side  of 
the  equation  by  the  square,  if  practicable,  let  both  roots  be  investigated  : 
and  then  multiply  "  greatest"  by  "least."  Or,  if  it  were  depressed  by  the 
biquadrate,  multiply  "  greatest"  by  the  square  of  "  least."  The  rest  of  the 
process  is  as  before. 

'  They  are  so  put,  as  that  one  condition  of  the  problem  be  fulfilled.  Su'r.  and  Ram. 

■^  Put  2  for  "  least"  root.     Its  square  4,  multiplied  by  the  coefficient  12,  is  48  :  which,  added 

to  1,  yields  a  square-root  7.     Statement:    C12    L2    G7    Al      Whence,    by   composition 

L2    G  7    A  1 

(§77),  138   g97.  '  Su'R,audRAM. 


J 


VARIETIES    OF    QUADRATICS.  249 

The  rule  is  clear  in  its  import. 

181.  Example  :  Tell  me  quickly,  mathematician,  the  number,  of  which 
tlie  square's  square,  multiplied  by  five  and  lessened  by  a  hundred  times  the 
square,  is  capable  of  yielding  a  square-root. 

Here  the  number  is  put  ya\.  Its  biquadrate,  multiplied  by  five,  and 
lessened  by  a  hundred  times  the  square  of  the  number,  h  yaw  5  yav  100. 
It  is  a  square.  Put  it  equal  to  the  square  of  ca,  and  the  root  of  the  square 
of  ca  is  ca  1.  Depressing  the  second  side  of  the  equation,  namely  ^a  w  t;  5 
yavlOO,  by  the  common  divisor,  square  of  j^a,  the  roots,  investigated  by 
the  rule  of  the  affected  square,'  come  out  L  10  G  20  or  Z  170  G  380. 
Depression  by  the  square  having  taken  place,  multiply  "greatest"  root  by 
"  least"  (§  179) ;  and  thus  "  greatest"  is  brought  out  200  or  646OO.  This  is 
the  value  of  ra.  "  Least"  root  is  the  value  of  the  colour  joined  with  the  co- 
efficient :  and  that  is  the  number  sought:  viz.  10  or  170. 

182.  Example:  Most  learned  algebraist!  tell  various  pairs  of  integer 
numbers,  the  difference  of  which  is  a  square,  and  the  sum  of  their  squares 
a  cube. 

Put  the  two  numbers  ya  1  and  ca  1.  Their  difference  is  ya  1  ca  1. 
Making  it  equal  to  the  square  of  ni,  the  value  of  ya  is  had,  ca  \  nivl. 
Substituting  with  this  for  ya,  the  two  quantities  become  ca  1  7iiv  1  and  ca  1. 
The  sum  of  their  squares  is  caw 2  niv.  ca  bh9,  nivvl.  It  is  a  cube. 
Make  it  then  equal  to  the  cube  of  the  square  of  ni ;-  and,  subtraction 
taking  place,  there  results,  in  the  first  side  of  equation,  niv  gh\  nivv  \; 
and,  in  the  second,  ca  f  2  ni  v.  ca  bh  2.  Multiplying  both  sides  by  two 
and  superadding  the  biquadrate  of  ni,  the  square-root  of  the  second  side  of 

'  Assumv  the  "least"  root  10.  Its  square  100,  multiplied  by  the  coefficient  5,  is  500.  This, 
added  to  the  number  100  with  the  negative  sign,  makes  400.  Its  root -20  is  "  greatest"  root. 
Statement  C  5  L  10  G  (-20,  or,  depression  by  the  square  having  previously  taken  place,) 
200    A  100.  SuR.  and  Ram. 

So   from  the  above  (C  5    LlO    G  20    A  100),  by  §77,    there   results   c5    ll     g2    ai: 

whence,  by  composition  of  like  (§  77),    i  *   G  9   A  \  ;    and,    by  composition   of  unalike  (ib.) 

C5   LlO  G20  A  100   roots  are  deduced  Z 170   ^380   a  1*00. 
L   4.  G  9  A     \ 

*  This  is  a  limitation  more  than  is  contained  in  the  problem. 

K  K 


250  TI'JA-G ANITA.  Chapter  VII. 

the  equation  is  caQ  nivl.  Depressing  the  first  side  by  the  biquadrate  of 
ni  as  common  divisor,  to  niv  2  ru  1,  the  roots  investigated  by  the  rule  of 
affected  scjuare,*  are  L  5  G7;  orZ29  G41.  Then  multiplying  "  greatest" 
by  square  of"  least,"  conformably  to  the  rule  (§  180),  it  comes  out  G  175, 
or  34481.  "Least"  root  is  the  value  of  «i.  Substituting  with  tliat,  the 
former  root  becomes  ca  2  ra25;orca2  rw  841.  Making  an  equation  of 
this  with  "  greatest"  root,  the  value  of  ca  is  obtained  100  or  I766I.  Sub- 
stituting these  values  respectively,  the  pair  of  numbers  is  brought  out  75 
and  100;  or  16821   and  I766I ;  and  so  forth. 

183.  Rule  :  comprised  in  a  stanza  and  a  half.  If  there  be  the  square  of 
a  colour  together  with  the  simple  unknown  quantity  and  absolute  number,* 
making  it  equal  to  the  square  of  another  colour,  find  the  root ;  and,  on  the 
other  side,  investigate  two  roots,  by  the  method  of  affected  square,  as  has 
been  taught.  Consider  the  "  least"  as  equal  to  the  first  root ;  and  "  greatest" 
as  equal  to  the  second. 

The  root  of  the  first  side  of  the  equation  having  been  taken,  if  there  be 
on  the  other  side  the  square  of  the  unknown  with  the  simple  unknown,  and 
with  or  without  absolute  number,  make  an  equation  of  that  remaining  side 
with  the  square  of  another  colour  and  take  the  root.  Then  let  the  roots  of 
this  other  be  investigated  by  the  rule  of  affected  square.  Of  the  two  roots 
so  investigated,  making  "  least"  equal  to  the  root  of  the  first  side  of  equa- 
tion, and  "  greatest"  equal  to  the  root  of  the  second,  let  the  values  of  the 
colours  be  sought. 

'  Put  5  for  "  least"  root.  Its  square  25,  multiplied  by  the  coefficient  2,  makes  50.  Subtract- 
ing one  (.for  the  negative  additive)  tlie  remainder  49  yields  a  square-root  7;  and  the  two  roots  art 
5  and  7. — Sua.  Ram.  By  §88 — 89,  the  roots  are  1  and  1.  By  composition  with  the  above 
C2L1GIAI*  They  are  112  g  17  a  1;  and  by  further  composition  C2  L  1  G  1  Al 
L5  G7  ^i  1  12   gl7  a  1 

they  are  1^9  g 4,1  al. 

'  A  variation  in  the  reading  of  this  passage  is  noticed  by  Su'ryada'sa  :  viz.  avyacta-rdpah  in- 
stead of  sdvyacta-rupah.  The  meaning,  as  this  is  interpreted  by  him  and  by  Ra'macrishn'a,  is,  if 
there  belioth  a  terra  of  the  unknown  and  absolute  number  besides  the  square  of  the  unknown. 
The  other  reading  may  be  explained  as  confined  to  one  term  (the  unknown)  besides  the  square. 
See  Sua.  and  Ram.  The  author  himself  in  his  comment  dispenses  with  the  third  term,  or  abso- 
lute number,  which  is  indeed  not  necessary  to  bring  the  form  within  the  operation  of  the  rule. 


VARIETIES    OF    QUADRATICS.  251 

184.     Example:     Say  in  what  period  (or  number  of  terms)  is  the  sum  of 

a  progression  continued  to  a  certain  period  tripled  ;  its  first  term  being  three 

and  the  common  difference  two  ? 

In  this  case  the  statement  of  the  two  progressions  is  l3  Ds  Fyal*    The 

l3D2Pc«l 

sums  of  these  progressions  are  yav  I    ya  2t     Making  three  times  the  first 

cavX    cal 

equal  to  the  second,  the  two  sides  of  equation  are  yav  3   ya6    Triphng 

cav  1    ca2 
both,  and  superadding  nine,  the  root  of  the  first  is  found  ya  3    ru  3.    Making 
the  second  side,  namely  ca  w  3    caQ    ru  9,  equal  to  the  square  of  7ii,  the 
two  sides  of  equation  become  cav  3    ca6     Tripling  these  and  superadding 

niv  I  ru9 
cine,  the  root  of  the  first  of  them  is  found  ca  3  ru3.  Roots  of  the  second 
(niv  3  ru  18)  investigated  by  the  rule  of  afi^ected  square,*  are  L9  G  15  or 
X.  33  G  57.*  IMaking  equations  of  "  least"  with  the  first  root,  namely 
^fl  2  ruS;  and  of  "  greatest"  with  the  second,  ca  3  7'u  3  ;  the  values  of  ^a 
and  ca  are  brought  out  2  and  4;  or  10  and  18.     So  in  every  [like]  instance. 

185 — 186.  Rules:  two  stanzas.  But,  if  there  be  two  squares  of  colours, 
"with  (or  without')  absolute  number,  assume  one  of  them  at  choice  as  (pra' 
criti)  the  affected  square,*  and  let  the  residue  be  additive :  and  then  pro- 
ceed to  investigate  the  root  in  the  manner  taught,  provided  there  be  mpre 
than  one  equation. 

186.     Or,  if  there  be  two  squares  of  colours  together  with  a  factum 

•  The  author  employs  the  initials  i,  u  and  ga  of  the  words  adya,  uttara  and  gachcha,  signifying. 
Initial  term,  Difference  and  Period  (or  number  of  terms)  of  a  progression.     See  Lil.  Ch.  4. 

•f-  By  the  rule  in  the  Lildvali,  for  the  sum  of  a  progression.     Lil.  §  lip. 

'  One  copy  here  inserts,  *L3  G5  A 2  and,  making  the  additive  ninefold,  Lp  G  15  A  18.' 
This  indication  of  the  manner  of  finding  the  roots  is,  however,  wanting  in  other  collated  copies  of 
the  text. 

•  Assume  9  for  "  least"  root :  its  square  81,  multiplied  by  the  coefficient  3,  is  2i3  :  from  which 
subtract  18  for  the  negative  additive;  and  the  remainder  225  gives  the  square-root  15.         Sua. 

'  Collated  copies  exhibit  "with:"  but  the  commentator  reads  and  interprets  "without;" 
(ar&pace  instead  ofaarupacSJ.    The  author's  own  comment  may  countenance  either  reading. 

•  See  note  at  the  beginning  of  Ch.  3. 

K  K  2 


SS2  Vl'JA-GAN'ITA.  Chapter  VII. 

(bh&vita)  ;  taking  the  square-root  [of  so  much  of  it  as  constitutes  a  square] 
let  the  root  be  made  equal  to  half  the  difference  between  the  residue,  divided 
by  an  assumed  quantity,  and  the  quantity  assumed. 

The  root  of  the  first  side  of  equation  having  been  taken,  if  there  be  on 
the  second  side  two  several  squares  of  colours  with  or  without  unity  (or  any 
absolute  number),  make  one  square  of  a  colour  the  subject  (pracrlti),'  and  let 
the  rest  be  the  additive.  Then,  proceeding  by  the  rule  (§  73)  let  a  multiple 
(by  one,  or  some  other  factor,)  of  the  same  colour  which  occurs  in  the  addi- 
tive, or  such  colour  with  a  number  (one,  or  another,)  added  to  it,  be  put 
for  the  "  least"  root,  selected  by  the  calculator's  own  sagacity  ;  and  thence 
find  the  "greatest"  root  (§  75).  If  the  coefficient  be  an  exact  square,  the 
roots  are  to  be  sought  by  the  rule  (§  95)  'The  additive  divided  by  an  assumed 
quantity,  &c.' 

If  there  be  a  (bh&vita)  product  of  colours,  then  by  the  above  rule  (§  186) 
the  root  of  so  much  of  the  expression  as  affords  a  root  is  to  be  taken  ;*  and 
that  root  is  to  be  made  equal  to  the  half  of  the  difference  between  the  quo- 
tient of  the  residue  divided  by  an  assumed  quantity  and  that  assumed  quan- 
tity.' 

But,  if  there  be  three  or  more  squares  or  other  terms  of  colours,  then  re- 
serving two  colours  selected  at  pleasure,  and  putting  arbitrary  values  for  the 
rest,  let  the  root  [of  the  reserved]  be  investigated. 

This  is  to  be  practised  when  there  is  more  than  one  equation.  But,  if 
there  be  only  one ;  then  reserving  a  single  colour,  and  putting  arbitrary 
values  for  the  rest,  let  the  root  be  sought  as  before. 

1 87.  Example :  Tell  two  numbers,  the  sum  of  whose  squares  multi- 
plied by  seven  and  eight  respectively  yields  a  square-root,  and  the  difference 
does  so  being  added  to  one. 

Let  the  numbers  be  put  ya  1,  ca\.  The  sum  of  these  squares  multiplied 
respectively  by  seven  and  eight,  is  yav7    ca  v  8.     It  is  a  square.     Making 

'  See  note  at  the  beginning  of  Ch.  3. 

*  The  term  consisting  of  the  product  of  two  factors  raay  be  thus  exterminated,  taking  with  it 
squares  of  both  colours  with  proper  coefficients  to  complete  the  square. — See  Sua. 

'  This  is  grounded  on  the  rule  of  §  95.  The  compound  square  has  unity  for  coefficient ;  and 
the  residue  is  the  additive  ;  the  "  least"  root,  which  is  the  root  of  that  square,  is  deduced  from  the 
additive  by  the  rule  cited;  and  needs  no  division,  the  square-root  of  the  coefficient  being  unity. 


VARIETIES    OF    QUADRATICS.  25S 

it  equal  to  square  of  ni,  and  subtracting;  the  two  sides  of  equation  are 
yav7  Adding  eight  times  the  square  of  ca,  the  root  of  the  second 

cav  h    niv  \ 

side  of  equation  is  ni  1 ;  and  roots  of  the  first  side,  viz.  yav7  cav8,  are  to 
be  investigated  by  the  method  of  the  affected  square.  Here  the  number 
(anca),  which  is  joined  with  the  square  of  i/a,  is  (pracnti)  the  subject  af- 
fecting it:  the  residue  is  additive:  C7,  A  caw  8*  Roots  found  by  the 
rule  (§  75),  assuming  ca%  are  L,  ca9.;  and  G,  ca6.  "  Greatest"  root  is  a 
value  of  ni ;  "least"'  is  so  of  ya.  Substituting  with  it  fox  ya,  the  two  num- 
bers become  ca  2,  c«  1 .  Again  the  difference  of  the  squares  of  these  multi- 
plied respectively  by  seven  and  eight,  together  with  one  added  to  it,  is 
cav9.0  ru\.  It  is  a  square.^  Proceeding  then  as  before,  "  least"  root 
comes  out  2  or  36.  This  is  a  value  of  ca.  Substituting  with  it,  the  two 
numbers  are  obtained :  viz.  4  and  2 ;  or  72  and  36. 

188.  Example  :  Bring  out  quickly  two  numbers  such,  that  the  sum  of 
the  cube  [of  the  one]  and  square  [of  the  other]  may  be  a  square ;  and  the 
sum  of  the  numbers  themselves  be  likewise  a  square. 

Put  the  numbers  ya\  ca\.  The  sum  of  the  square  and  cube  of  these  is 
yavl  ca gh\.  It  is  a  square.  Making  it  equal  to  the  square  of  ni  and 
adding  cube  of  ca,  the  root  of  one  side  is  ni  1 ;  and,  of  the  other  (viz.  yavl 
ca  gh  1)  roots  are  to  be  sought  by  the  method  of  the  affected  square.  The 
number,  which  is  joined  with  the  square  of  ya,  is  the  coefficient ;  the  rest 
is  the  additive :  C,  yav  \  A,cagh\.  Then,  by  the  rule  (§95),  taking  ca 
for  the  assumed  quantity  under  that  rule,  the  two  roots  come  out  cav\  ca\ 
and  cav^  ca^.  "  Least"  root  is  value  of  ya.  Substituting  with  it  for  ya, 
the  two  numbers  are  cav^  ca\  and  ca  1.  The  sum  of  these  \scav\  ca\' 
It  is  a  square.     Making  it  then  equal  to  pi;  and  multiplying  both  sides  by 

•  If  the  "least"  root  be  put  ca2;  the  "greatest,"  as  inferred  from  it,  (§75)  is  ca  6.— Su'r. 
Square  of  2  multiplied  hy  pracrUi  7,  is  28  ;  and,  with  the  additive,  36;  the  square-root  of  which 
» 6.  Ram. 

Put  it  equal  to  square  of;>;;  and  proceed  to  investigate  the  root  of  ca  r  20  ru  1.  Assume  for 
"  least"  root  2.  Its  square  4,  multiplied  by  20  and  added  to  ],  is  81 :  the  square-root  of  which  is 
p.    Then  by  composition  of  like  (§  77)  C  20  L  2  G9  A  1  other  roots  are  deduced  1  3(5  [g  l6"l], 

L2  Gp  Al  Sun.  and  Ram. 


854  VrJA-G ANITA.  Chapter  VII. 

four,*  and  adding  unity,  the  root  of  the  first  side  is  ca  2  rul;  and  roots  of 
the  second  (viz.  p'lvS  ru  1)  investigated  by  the  method  of  the  affected 
square  are  6  and  17,*  or  35  and  99.  Making  "greatest"  root  ecjual  to  the 
root  of  the  foregoing  side  of  equation  {ca  2  ru  I)  the  value  of  ca  comes  out 
8  or  49.  Substituting  therewith,  the  two  numbers  are  found  28  and  8,  or 
11 76  and  49. 

Or  let  two  numbers  be  put  ya  vQ  yav  7.  The  sum  of  these  is  of  itself 
obviously  a  square,  ya  v  9-  The  sum  of  the  cube  and  square  of  these  is 
ya  V  gh  S  yavc  49-  It  is  a  square.  Make  it  equal  to  square  of  ca.  De- 
pressing the  side  of  the  equation  by  the  biquadrate  o^ ya,  and  proceeding  as 
before  taught,'  the  value  of  ^a  is  obtained  2,  or  7,  or  3.  Substituting  there- 
with, the  two  numbers  are  found  8  and  28  ;  or  98  and  343;  or  18  and  63.* 

I89.  Example:  Tell  directly  two  numbers  such,  that  the  sum  of  their 
squares,  added  to  their  product,  may  yield  a  square-root :  and  their  sum, 
multiplied  by  that  root  and  added  to  unity,  may  also  be  a  square. 

Let  the  numbers  be  put  j/a  1,  ca  1.  The  sum  of  their  squares,  added  to 
their  product,  is  yav  I  ya.  ca  bh\  cav  \.  This  has  not  a  square-root. 
Therefore  putting  it  equal  to  square  of  ni,  and  adding  square  of  ca,^  and 
multiplying  by  thirty-six,  the  root  of  the  side  involving  ni  is  obtained,  viz. 
ni  6 ;  and  the  other  side  is  ya  v  36  ya.  ca bh  36  cav  36:  in  which  the  root 
of  so  much  of  it  as  affords  a  square-root  is  to  be  taken  by  the  preceding  rule 
(§  186)  viz.  ya6  ca  3,  and  the  residue,  namely  ca  v  27,  being  divided  by  ca 
as  an  assumed  quantity  [§  95],  and  from  the  quotient  the  same  assumed 

'  After  reducing  to  a  common  denomination  and  dropping  tbe  denominator. — Ram.  Multiply- 
ing both  sides  by  eight.  SuR. 

■*  The  commentators  (Su'r.  and  Ram.)  direct  6  to  be  put ;  and  proceeding  by  §  75,  deduco 

G  17.    But,  if  1  were  put  tentatively,  it  would  answer;  G  being  in  that  case  3  ;  and  the  further 

pair  of  roots  is  derived  from  composition  of  these  sets  by  §  77,  viz.  C.  8    I^  1    G    3    A  1    whence 

L6   G\7    A  I 

by  cross  multiplication,  &c.  135    g  99    »!•    The  lower  numbers  seem  to  have  been  omitted  by 

the  author  and  commentators,  because  the  numbers  sought  (ca  being  1)  would  come  out  0  and  1, 

which  they  consider  to  be  unsatisfactory  for  an  answer. 

'  See  §180. 

♦  Put  2,  3  or  7  for  "least"  root:  the  "greatest"  is  9,  11  or  21;  which  multiplied  by  th» 
square  of"  least"  ($  180)  give  36,  ^9,  or  1029. 

*  That  is,  bringing  it  back,  after  subtraction,  to  the  same  side  on  which  it  first  stood. 


k 


VARIETIES    OF    QUADRATICS.  255 

quantity  being  subtracted,  and  the  remainder  halved  [ibid.],  gives  ca  \3 ; 
■which,  made  equal  to  that  root,  brings  out  the  value  ofya ;  viz.  ca  4.  Sub- 
stituting with  this,  the  two  numbers  are  found  ca^  and  ca  1.  The  sum  of 
their  squares  cav  ^*,  added  to  their  product  cav  f,  is  cav  V  :  the  square- 
root  of  which  is  ca  \.  The  sum  of  the  numbers,  ca  f ,  multiplied  by  this, 
with  unity  added,  is  ca  v  *-/  ru  ^.  Making  this  equal  to  the  square  of  pi, 
"  least"  root'  found  by  investigation,  is  6  or  180.  It  is  the  value  of  ca. 
Substituting  with  it,  the  two  numbers  come  out  10  and  6  ;  or  300  and  180. 
In  like  manner  a  multiplicity  of  answers  may  be  obtained. 

190.  Example  of  a  certain  ancient  author.*  Tell  me  quickly,  algebraist, 
two  numbers  such,  that  the  cube-root  of  half  the  sum  of  their  product  and 
least  number,  and  the  square-root  of  the  sum  of  their  squares,  and  those  ex- 
tracted from  the  sum  and  difference  increased  by  two,  and  that  extracted 
from  the  difference  of  their  squares  added  to  eight,  being  all  five  added  to- 
gether, may  yield  a  square-root :  excepting,  however,  six  and  eight. 

The  conditions  of  the  problem  being  numerous,  the  solution,  unless  at 
once,  does  not  succeed.  The  intelligent  algebraist  must  therefore  so  put 
the  quantities,  as  that  all  the  conditions  may  be  answered  by  one  symbol.' 
Accordingly  the  two  quantities  are  put  yav  \  ru\  and  ya  2.  The  cube- 
root  of  half  the  sum  of  their  product  and  the  least  number  is  ya\.  The 
square-root  of  the  sum  of  their  squares  \s  yavl  ru  ].  The  square-root  of 
their  sum  [increased  by  two]  is  ya  1  ru\.  The  square-root  of  their  differ- 
ence [increased  by  two]  \s  ya  \  ru  I.  The  square-root  of  the  diff'erence  of 
their  squares  [with  eight  added]  is  yav  I     ru  3. 

The  sum  of  these  [five]  is  yav 2  ya  3  ruk.  It  is  a  square.  Make  it 
equal  to  square  of  ca.  Multiplying  both  sides  of  equation  by  eight,  and 
adding  the  absolute  number  nine,*  the  root  of  the  first  side  is  ya^   ru3; 

•  By  rule  §  75,  put  6;  and  proceeding  as  there  indicated,  its  square  36,  multiplied  by  the  co- 
efficient «5p,  is  l£±&  ;  and,  with  the  additive  (§),  S-'^'*  :  of  which  the  root  is  V  i  o"",  abridged,  15. 
Therefore  L6  G  15,  and  by  composition  (§  77)  L  180   G  449.  Sua.  Ram. 

*  Introduced  to  exhibit  facility  of  solution.  Ram. 

*  The  two  quantities  must  be  put  such,  that  the  five  roots,  which  are  prescribed,  may  be  pos- 
sible. SuR. 

♦  See§  131^ 


256  VI'JA-G  ANITA.  Chapter  VII. 

and  roots  of  the  other  (namely  of  cavS  ru  25)  investigated  by  the  method 
of  the  affected  square  are  5  and  15;  or  30  and  85;  or  175  and  495. 
Making  an  equation  of  "greatest"  root  with  the  former  (yaA,  ru  3)  the 
value  ofya  is  obtained  3,  or  V,  or  123.  By  substituting  with  the  vaUie  so 
found,  the  two  numbers  come  out  8  and  6:or^  and  41 ;  or  15128  and 
246 ;  and  in  hke  manner,  many  other  ways. 

Or  else  one  quantity  may  be  put  square  of  yfl  added  to  twice  i/a  ;  and  the 
other  twice  ya  less  two  absolute :  viz.  yav\    ya^  and  ya  2    ru  2. 

Or  one  quantity  may  be  put  square  of  ya,  less  twice  ya-,  and  the  other 
twice  j^fl  less  absolute  two:  viz.   yav  \  ya\  and  j/a  2   rM2. 

Or  one  quantity  may  be  square  of  ya  with  four  times  ya  and  three  abso- 
lute; and  the  other  twice  j/a  with  four  absolute  :  viz.  yav\  ya^  ruS  and 

ya  2   ru  4. 

"  As  supposition,  which  thus  is  a  thousand-fold,  is  to  the  dull  abstruse, 
the  mode  of  putting  suppositions  is  therefore  unfolded  in  compassion  to 
them." 

191 192.     Rule:  two  stanzas.     Let  the  root  of  the  difference  be  first 

put,  an  unknown  number,  with  or  without  absolute  number:  that  root  of 
the' difference,  added  to  tlie  square-root  of  the  quotient  of  the  additive  of 
the  difference  of  squares  divided  by  the  additive  of  the  difference  of  the 
numbers,  will  be  the  root  of  the  sum.  The  squares  of  these  with  their  ad- 
ditives subtracted,  are  the  difference  and  sum :  from  which  the  numbers  arc 
found  by  the  rule  of  concurrence.' 

193.  Example:  Tell  me,  gentle  and  ingenuous  mathematician,  two 
numbers,  besides  six  and  seven,  such  that  their  sum  and  their  difference, 
with  three  added  to  each,  may  be  squares ;  that  the  sum  of  their  squares  less 
four,  and  the  difference  of  their  squares  with  twelve  added,  may  also  be 
squares ;  and  half  the  product  less  the  smaller  number  may  be  a  cube ;  and 
the  sum  of  all  their  roots,  with  two  added,  may  likewise  be  a  square. 

Put  the  symbol  of  the  unknown  less  unity  for  the  root  of  the  differ- 
ence:  viz.  yal  ru\.  Then  by  that  analogy  (and  according  to  the  last 
rule)  the  two  numbers  are  put  yav\    rul   and  ya9..*     The  roots  are 

■  Lil.  §  55.  . 

*  Put  for  the  root  of  the  difference  with  three  added  to  render  it  square,  yal   rul.    Add  the 


VARIETIES    OF    QUADRATICS.  257 

j/fl  1   ru  I  ;  ya  \    /'w  1 ;   yav\  ;  yav  \    rw  4 ;  ya\-     The  sum  of  these,  with 
two  added  to  it,  \syav9.  ya3   ru*-!.     It  is  a  square.     Let  it  be  equal  to' 
square  of  ca.     The  two  sides  of  equation  become  yav  9.    ya3     Multiplying 

ca  v  \  ru'2 
by  eight  and  adding  nine,  the  root  of  the  first  side  is  ya  4  ru  3;  and  the 
roots  of  the  second  (ca  v  8  ru  25)  by  the  method  of  the  affected  square  are 
L5  G  15  or  Z  175  G495.*  "Greatest"  root  being  equal  to  the  former 
root  i^ya  4  ru  3),  the  value  of  ya  is  obtained  3  or  1 23 ;  and,  substituting 
with  these  values,  the  two  numbers  come  out  7  and  6  or  15127  and  246.t 

194.  Example  by  an  ancient  author :'  Calculate  and  tell,  if  you  know, 
two  numbers,  the  sum  and  difference  of  whose  squares,  with  one  added  to 
each,  are  squares :  or  which  are  so,  with  the  same  subtracted. 

In  the  first  example,  let  the  squares  of  the  numbers  be  put  yav  ^s  and 
yav 5  ru\.  The  sum  and  difference  of  these  with  unity  added,  afford 
each  a  square-root.  Tlie  square-root  of  the  first  assumed  quantity  is  one  of 
the  numbers,  Viz.ya^.  Roots  of  the  second,  namely  j/a  1*5  ru\,  investi- 
gated by  the  method  of  the  affected  square,*  are  1  and  2,  or  S7  and  38.  Of 
these,  "  greatest"  root  is  the  second  number,  and  "  least"  is  a  value  of  ya  ; 
from  which  the  first  number  is  deducible.  Substituting  then  with  that  value, 
the  two  numbers  arc  2  and  2,  or  34  and  38. 

square-root  of  the  quotient  of  the  additive  of  difference  of  squares  by  the  additive  of  difference  of 
numbers,  viz.  ru2,  the  sum  is  ^a  1  rul;  the  root  of  the  sum  with  three  added  to  render  it 
square.  Their  squares  are  yav  I  yai  ru  \  and  yav  I  ya2  rul;  and,  subtracting  the  addi- 
tives of  the  sum  and  difference,  there  remain  the  sum  and  difference  of  the  numbers,  ya  v  I  ya  2 
ru'2  and  yav\   ya  1    ru2.     Half  the  sum  and  difference  of  these  are  the  numbers  themselves. 

*  By  §  75,  the  first  roots  are  had  by  position  :  the  next  by  combination,  under  §  77- 

t  The  same  is  found  by  the  process  of  the  foregoing  rule.  Let  the  root  of  the  difference  be  put 
122.  Divide  the  additive  of  the  difference  of  the  squares,  by  the  additive  of  the  numbers,  12  by  3 ; 
the  quotient  is  4.  Its  square-root  is  2.  Add  this  to  the  root  of  the  difference,  the  result  is  the 
root  of  the  sum:  (2  added  to  122;  making  124.)  The  squares  of  these,  less  the  additives,  give  the 
sum  and  difference  :  14881  and  15373.  Whence,  by  the  rule  of  concurrence  (,Lil.  §55)  the  two 
numbers  are  deduced,  15127  and  246.  Sun.  and  Ram. 

^  It  comprises  two  distinct  examples.  Su'ii. 

♦  Put  tentatively  1  for  "least"  root;  and  the  "  greatest"  by  §75  is  found  2.  Then  combining 
like  roots  (577),  there  result  L  4  G  9.  Combining  these  dissimilar  roots  (ibid.)  others  result 
adapted  to  the  second  example  1  17  g38;  or,  combining  like,  111  g  \G\. 

L  L 


258  VIJA-GANITA.  Chapter  VII. 

In  the  second  example,  similarly,  the  fust  number  is  ya  2 ;  and,  for  the 
second,  roots  are  to  be  investigated  from  this  yav5  ru  1,  by  the  method  of 
the  affected  square.  They  are  4  and  9  ;  or  72  and  l6l.  With  "least"  the 
first  root  (or  number,)  is  raised ;  and  "  greatest"  is  the  second.  Thus  the 
two  numbers  come  out  8  and  9  ;  or  144  and  16 1. 

Here  such  number,  as,  with  the  least,  whether  added  or  subtracted,  yields 
a  square-root,  must  be  the  second  coefficient.'     The  way  to  find  it  is  as  follows. 

Let  the  least  square  quantity  [that  is,  the  coefficient]  be  put  4.  The  se- 
cond, with  this  added  or  subtracted,  must  afford  a  scjuare-root.  Being  dou- 
bled, it  is  8.  This  is  the  difi^erence  of  the  squares  of  certain  two  numbers ; 
and  it  is  consequently  equal  to  the  product  of  the  sum  and  difference.  The 
difference  of  the  numbers,  therefore,  is  assumed  2:  and  by  the  rule  (Z?/.  §  57) 
for  finding  two  numbers  from  the  difference  of  squares,  and  difference  of  the 
numbers,  the  roots  of  the  difference  of  squares  and  of  the  sum  of  the  squares 
are  found  1  and  3.  Adding  the  least  square  quantity  to  the  square  of  the 
first,  or  subtracting  it  from  the  square  of  the  second,  there  results  the  second 
[viz.  5].  Here  the  least  square  quantity  must  be  so  devised,  as  that  the  se- 
cond may  be  an  integer. 

Or,  in  like  manner,  another  is  assumed  36.  Doubled,  it  is  72.  This  is 
the  difi'erence  of  two  squares:  and  six  being  put  for  the  difference  of  the 
numbers,  the  second  is  brought  out  45.  Or,  with  four  put,  it  comes  out  85 ; 
or,  with  two,  325.* 

Or  else  another  ground  of  assumption  may  be  shown,  as  follows.  The 
sum  of  the  squares  with  twice  the  product  of  the  two  quantities  added  or 
subtracted,  must  afford  a  root.  That  twice  the  products  of  two  quantities 
may  be  an  exact  square,  one  should  be  put  a  square,  and  the  other  half  a 
square;  for  the  product  of  squares  is  square.  Thus  they  are  assumed,  one  a 
square,  the  other  half  a  square:  lands.  Twice  their  product  is  4.  This  is 
least  square  number  [or  coefficient].  The  sum  of  their  squares  is  5.  This  is 
second  quantity. 

Or  let  the  one  square,  and  the  other  half  square,  be  9  and  2.  Twice  their 
product  is  36.  This  is  the  least  square  number.  The  sum  of  the  squares  is 
85.     This  is  second  quantity. 

'  Tdtad-iyacta,  the  known  number  annexed  to  t/kat  (or  ydvat-iivat)  the  unknown  quantity, 
See  the  author's  remark  towards  the  close  of  his  comment. 
*  And  similarly  a  multiplicity  may  be  found.  Sua. 


VARIETIES    OF   QUADRATICS.  259 

These  known  numbers  are  multiplied  by  square  of  yavat-tdvat :  and,  in 
the  first  example,  the  second  quantity  has  unity  subtracted  from  it;  in  the 
second  example,  it  must  have  the  same  added  to  it.  So  doing,  those  two 
square  quantities  are  so  contrived  as  to  fulfil  both  conditions  of  the  problem. 
But  having  extracted  the  square  root  of  the  first,  the  root  of  the  second  is  to 
be  found  by  the  method  of  the  affcctetl  square,  as  before  observed. 

Thus  [the  problem  is  solved]  many  ways. 

195 — 196.  Rule:  two  stanzas.  In  such  instances,  if  there  remain  the 
[simple]  unknown  with  absolute  number,  find  its  value  by  making  it  equal 
to  the  square  or  [other  power]  of  another  symbol  with  unity  :*  and  substi- 
tuting with  this  value  in  [the  expression  of]  the  quantity,  proceed  to  the 
further  operation,'  making  the  root  of  the  former  equal  to  the  other  symbol 
and  unity.  ' 

After  the  root  of  the  first  side  of  the  equation  has  been  taken,  if  there  be, 
on  the  other  side,  the  simple  unknown  with  absolute  number,  or  without  it; 
In  such  case,  making  an  equation  with  the  square  of  another  colour  Avith 
unity,  and  thence  bringing  out  the  value  of  that  unknown,  and  substituting 
with  this  value  in  the  expression  of  the  quantity,  proceed  again  to  the  fur- 
ther operation ;  and,  in  so  doing,  make  an  equation  of  the  root  of  the  first 
side  with  the  other  symbol  and  unity.  But,  if  there  be  no  further  operation, 
then  the  equation  is  to  be  made  with  a  known  square  and  so  forth. 

197.  Example:  If  thou  be  expert  in  the  extirpation  of  the  middle  term 
in  analysis,  tell  the  number,  which  being  severally  multiplied  by  three  and 
five,  and  having  one  added  to  the  product,  is  a  square. 

In  this  case  put  the  number 3/fl  I.  This,  tripled,  with  one  added,  is ya  3 
ru  \.  It  is  a  square.  Making  it  equal  to  square  of  cc,  and  adding  unity  on 
both  sides,  [to  replace  it  on  its  original  side,]  the  root  of  the  side  of  equation 
containing  ca  is  c«  1.     Making  the  other  side,  namely  i/rt  3    ru  \,  equal  to 

'  Since  the  root  cannot  in  such  ca.se  be  sought  by  the  rule  of  Chapter  3,  as  there  is  not  an  af- 
fected square  :  for  the  simple  unknown  only  remains:  hut  (pracrcti)  an  affected  square  consists  in 
a  square  of  the  unknown.  Its  root  therefore  can  only  be  possible  by  equating  it  with  the  square 
of  some  quantity  whatsoever.  Sur. 

*  Not,  if  no  further  operation  depend:  for  the  value  would  be  an  unknown.  But  make  it  equal 
to  a  known  square,  &c.  and  thus  the  value  is  absolute.  Ram. 

L  L  2 


260  VIJA-GANITA.  Chapter  VII. 

the  square  of  thrice  n't  joined  with  unity,  viz.  niv  9  ni  6   ru  1,  the  value 

ofya  is  obtained;  substituting  with  which  the  number  conies  out  ni  v  3 

ni  2.     Again,  this  multipUed  by  five,  with  one  added  to  the  product,  is 

nl  V  15     ni  10     ru  I.     It  is  a  square.     Making  it  equal  to  square  of  pi,  the 

equation  after  Hke  subtraction  is  ni  v  15     ni  10     Multiplying  both  sides  by 

piv  1     ru    1 

fifteen  and  adding  twenty-five,  the  root  of  the  first  side  is  ni  15  ru5.  Roots 
of  the  second,  viz.  pi  v  15  ru  10,  investigated  by  the  method  of  theaflFected 
square,'  arc  9  and  35,  or  71  and  275.  "  Least"  is  the  value  of  pi.  "  Greatest" 
being  equal  to  the  root  of  the  first  side  of  the  equation  ni  \5  ru  5,  the  value 
of  ni  comes  out  2  or  18.  Substituting  with  its  value  for  it,  the  number  is 
found,  16  or  1008. 

Or  let  the  number  be  7/a  1 ;  and,  as  this  tripled,  with  one  added,  is  a  square, 
make  it  equal  to  square  of  ca;  and,  after  equal  subtraction,  find  the  value  of 
1/a;  which,  substituted  accordingly,  gives  for  the  number  ca  v  ^  ru  •§■.  Or 
let  its  value  be  so  put  at  the  first,  that  one  of  the  conditions  may  be  of  itself 
fulfilled,  cav-^  ru  ^.  This  multiplied  by  five,  with  one  added  to  the  pro- 
duct, cav  ^  fu^,  yields  a  square  root.  Making  it  equal  to  square  of  ni, 
the  root  of  the  side  involving  ni  being  extracted  hni  1;  and  the  roots  of  the 
other  side  cav  ^  ru  f,  being  investigated  by  the  method  of  the  affected 
square,  are  7  and  S).  "  Least"  is  value  of  ca,  and  substituting  with  it  (in 
ca  V  \    ru  -f)  the  number  is  found  16;  the  same  as  before. 

198.  Example  by  an  ancient  author:  What  number,  multiplied  by  three, 
and  having  one  added  to  the  product,  becomes  a  cube;  and  the  cube-root, 
squared  and  multiplied  by  three,  and  having  one  added,  becomes  a  square? 

Let  the  number  be  put  j/a  1.  This  tripled,  with  one  added,  is  j/a  3  ru  1. 
It  is  a  cube.     Making  it  equal  to  cube  of  ca,  the  value  of  j/a  is  found 


'  Put  1    for  "  least"  root:    the  "  greatest"   by  rule  §  75  is   5.      Then    by   composition 

Cl5    Ll    G5    A  10  other  roots  are  found,  L  10   G 40    ^  100 ;  whence,  by  §  79,   ll    g4    al; 
Ll    G5    AlO 

and  by  composition  C  15    Ll    G5    A  10  liiie  roots  are /p   g  35   a  10;  and  by  further  corabina- 
1  1     g4     a    1 

tion  C  15    19  g35   a  10  they  come  out  ^71    y275    #10.    That  is,  1  and  5  ;  or  9  and  35;  or 
1  1    g  4    a    1 

71  and  275.    The  first  pair  is  not  noticed,  apparently  because  the  number  thence  deduced  would 

be  cipher. 


VARIETIES  OF  QUADRATICS.  2G1 

ca  gh  1     ru  1     The  cube-root  of  three  times  that,  with  unity  added  to  the 

3 
product,  being  squared  and  tripled,  and  having  one  added  to  it,  hcav3   ru\. 

It  is  a  square.  Put  it  equal  to  square  of  wi 3  ru  I:  and  the  equation  is 
cav  3  Adding  unity  to  both  sides,    the  root  of  the  second  side  is 

ni  V  9    niS 

ni  3  7'u  1;  and  those  of  the  other,  investigated  by  the  method  of  the  af- 
fected square,'  are  L4  G  7-  Substituting  as  before  with  the  value  of  ca,' 
the  number  comes  out  21  (or  ^^). 

199.  Example:  Say  quickly  what  are  two  numbers,  of  which,  as  of  six 
and  five,  the  difference  of  the  squares  being  severally  multiplied  by  two  and 
by  three,  and  having  three  added  to  the  products,  shall  in  both  instances  be 
square,? 


200.  Maxim;  Intelligent  calculators  commence  the  work  sometimes  from 
the  beginning  [of  the  conditions],  sometimes  from  the  middle,  sometimes 
from  the  end;  so  as  the  solution  may  be  best  effected.' 

In  this  instance,  let  the  difference  of  squares  be  putt/a  1.     This  doubled, 

with  three  added,  (ya  2    ru  3)  is  a  square.     Make  it  equal  to  square  of  ca; 

and  with  the  value  of  3/a  thence  deduced,  substitute  for  the  quantity,  which 

thus  becomes  ca  v  I    ru3.     This  again  tripled,  with  three  added,  is  a  square. 

2 

Make  it  equal  to  square  o£  ni;  and,  like  subtraction  taking  place,  the  sides 

of  equation  are  ca  v  3     ru  0     Multiplying  them  by  three,  the  root  of  the 

ni  w  2     ru  3 
first  is  ca  3;  and  the  roots  of  the  second  (tii  v6   ru  9)  investigated  by  the 

'  Put  1  for  "  least"  root,  the  greatest  is  2  by  §  75.  Then  by  composition  of  like,  another  pair 
of  roots  is  thence  found  (§  77)  L  4  G  7 ;  and  by  combination  of  unalike,  another  pair  1  1 5  g  26'. — 
Su'r.    The  first  pair  is  unnoticed  as  it  would  here  also  bring  out  the  number  required,  a  cipher. 

*  III  the  expression  ca  g/<  1    ml.     Cubeof4is64;  less  one,  is  63;  divided  by  3,  is  21. — Su'u, 

o 

So  cube  of  15  is  3375;  less  one,  is  3374 ;  divided  by  3,  is  111*. 

'  Sometimes  assumption  is  commenced  by  intelligent  persons  from  the  beginning  of  the  condi- 
tions as  enunciated  ;  sometimes  from  the  middle  ;  sometimes  from  the  end,  by  inversion  :  so  as  the 
work  of  solution  be  accomplished.  That  is,  in  the  instance,  the  difference  only  is  put  as  unknown ; 
without  putting  the  numbers  themselves  so.  SuR.     Ram. 


j36a  VI'JA-GAN'ITA.  Chapter  VII. 

nictlwxl  of  the  affi-cted  square,'  are  6  and  15,  or  60  and  147.  "  Greatest" 
being  equalled  to  the  [root  of  the]  first  side,  the  value  of  ca  is  obtained  5,  or 
49.  And  substituting  with  this  value,  the  difference  of  squares  comes  out 
11,  or  1199.'  Then  by  the  rule  (Lil.  §37)  for  finding  two  numbers  from 
difference  of  squares  and  difference  of  the  simple  quantities,  putting  unity 
for  their  difference,  the  two  numbers  are  found,  5  and  6,  or  599  and  6OO: 
or,  putting  eleven  for  their  difference,  the  two  numbers  are  49  and  60. 

201.  Rule:  a  stanza  and  a  half  If  the  simple  unknown  be  multiplied 
by  the  quantity  which  was  divisor  of  the  square,  &c.  [on  the  other  side] ;  then, 
that  its  value  may  in  such  case  be  an  integer,  a  square  or  like  [term]  of  ano- 
ther symbol  must  be  put  equal  to  it:  and  the  rest  [of  the  operations]  will  be 
as  before  taught. 

In  the  case  of  a  square,  &c.  and  in  that  of  a  pulverizer  or  the  like,  after  the 
root  of  one  side  of  the  equation  has  been  taken,  if  there  be  on  the  other  side 
an  unknown  multiplied  by  the  quantity  which  was  divisor  of  the  square,  &c. 
the  square  and  other  term  of  another  symbol  together  M'ith  absolute  number 
added  or  subtracted,  must  be  put  equal  to  it;  that  so  its  value  may  come 
out  integer.     The  rest  [of  the  steps]  are  as  taught  in  the  preceding  rides. 

202.  Example :  What  square,  being  lessened  by  four  and  divided  by 
seven,  yields  no  remainder?  or  what  other  square,  lessened  by  thirty  ?  If 
thou  know,  tell  promptly. 

Put  the  number  i/a  1.  Its  square,  less  four,  and  divided  by  seven,  is  ex- 
hausted. Let  the  quotient  be  ca.  Making  an  equation  of  the  divisor  mul- 
tiplied by  that,  with  this  yav  1  ru  4,  the  root  of  the  first  side  hi/a  1. 
Since  the  other  side,  ca  7  rM4,  yields  no  root,  put  it  equal  to  square  of 
seven  ni  and  two  absolute.  The  value  of  ca  is  had  without  a  fraction  niv7 
ni  4 :  and  the  quantity  put  is  the  root  of  the  second  side  of  equation,  or 
ni7   ru2.     This  being  equal  to  the  root  of  the  first  side,  or^a  1,  the  value 

•  The  lowest  number,  which  answers  for  "  least"  root,  found  by  position  (§  75)  is  6 ;  and  the 
corresponding  "greatest"  is  15.  From  which  by  §79  are  deduced  L  2  G  5  A  1;  and  by  combi- 
nation of  uiialike  (§  77)  C  6   L  6  G  15    A  9,  another  pair  of  roots  is  derived  1  60    g  147    a  9- 

L2  G    5^1 

»  Square  of  49  is  2401  ;  which,  less  3,  is  2398  ;  and  halved,  II99. 
'  The  unfinished  stanza  is  completed  at  §  208. 


VARIETIES   OF  QUADRATICS.  263 

of  ya  is  ni  7    ru  2,  with  the  additive.     It  comes  out  9  ;^  and  the  square  of 
this  will  be  the  number  sought,  81. 

For  the  instruction  of  the  dull,  the  way,  which  is  to  be  be  followed  in  the 
selection  of  another  symbol,  is  set  forth  by  ancient  authors. 

203 — 205.  Rule:  three  stanzas.  Choosing  a  number  such  that  its  square, 
divided  by  the  divisor,  may  yield  no  residue,  as  also  the  same  number,  mul- 
tiplied by  twice  the  root  of  the  absolute  number;  let  another  colour  be  put 
multiplied  by  that  [as  coefficient],  and  with  the  root  of  the  absolute  numbei- 
added  to  it. 

fi04.  But,  if  the  absolute  number  do  not  yield  a  square-root,  then,  after 
abrading  the  number  by  the  divisor,  add  [to  the  residue]  so  many  times  the 
divisor  as  will  make  a  square.*  If  still  it  do  not  answer,  [the  problem  is]  im- 
perfect. 

205.  If  by  multiplication'  or  addition  the  first  [side  of  equation]  was 
made  to  afford  a  square  root ;  in  that  case  also,  the  divisor  [is  to  be  retained], 
as  enunciated  by  the  conditions;  but  the  absolute  number,  as  adjusted  by 
subtraction  and  so  forth,  is  right.* 

Such  a  number,  as  that  its  square  divided  by  the  divisor  shall  be  exhausted; 
that  is,  yield  no  residue ;  and  the  same  number  multiplied  by  two  and  by 
the  square-root  of  the  absolute  number,  being  divided  by  the  divisor,  shall  be 
in  like  manner  exhausted,  yielding  no  remainder;  by  such  coefficient,  let 
another  colour  be  multiplied  and  so  be  put  with  the  root  of  the  absolute 
number.  But,  if  there  be  not  a  root  of  the  absolute  number,  then,  the  ab- 
solute number  having  been  abraded  by  the  divisor,  superadd  [to  the  residue] 
so  many  times  the  divisor  as  will  make  a  square.  Let  its  square-root  be 
[used  for]  the  absolute  root.  Even,  with  so  doing,  if  a  square  be  not  pro- 
duced, then  that  example  must  be  deemed  imperfect  and  wrong.  If  the 
first  side  of  equation  multiplied  by  some  number,  or  with  one  added  to  it, 

'  Putting  unity  for  ni. — Su'k.     Supposing  2,  it  comes  out  l6;  or  with  3,  it  is  23. 

*  And  then  proceed  according  to  the  foregoing  rule,  using  its  root  as  root  of  the  absolute 
number. 

'  The  commentator  Su'ryada'sa  reads  hituA  and  interprets  it '  subtracting  ;'  but  collated  copies 
of  the  text  exhibit  halwd,  multiplying:  and  this  seems  the  preferable  reading.     See  §  128. 

♦  For  the  purpose  of  the  preceding  rule  (§  204.). 


264  Vl'JA-GAN'ITA.  Chapter  VII. 

afford  a  square-root ;  in  such  case  the  divisor  should  be  taken  as  enunciated, 
and  not  as  either  multipHcd  or  divided:  but  the  absolute  number  is  to  be 
taken  precisely  as  it  stands  when  equal  subtraction  has  beei;  made. 

The  like  is  also  to  be  understood  in  the  case  of  a  cube:  as  follows.  Such 
number,  as  that  its  cube  divided  by  the  divisor  may  be  exhausted,  exhibiting 
no  residue,  and  the  same  number  multiplied  by  three  and  by  the  cube-root  of 
the  absolute  number,  being  divided  by  the  divisor,  may  also  be  exhausted; 
by  such  coefficient  let  another  colour  be  multiplied  and  so  be  put  together 
with  the  cube-root  of  the  absolute  number.  If  there  be  not  a  cube-root  of 
the  absolute  number,  then,  after  abrading  the  number  by  the  divisor,  add  [to 
the  residue]  so  many  times  the  divisor,  as  may  make  a  cube.  Then  the 
cube-root  is  treated  as  root  of  the  absolute  number.  Even  with  so  doing,  if 
there  be  not  a  complete  cube,  the  instance  is  wrong.  This  is  to  be  applied 
further  on.* 

To  proceed  to  the  second  example  (§  iiOS).  Let  the  number  be  put  ya  1. 
Its  square  \s  yav  \.  Doing  with  it  as  directed,  the  root  of  the  first  side  is 
ya  1  ;  and  treating  the  second  side,  ca  7  ru  30,  as  prescribed  by  the  rule 
(§  204),  after  abrading  the  absolute  number  by  the  divisor,  superadding  twice 
the  divisor,  viz.  14,  the  root  is  ru  4.  By  making  an  equation  of  the  square 
of  seven  ni  with  this  added  («/'  7  ru  4)  the  value  of  ca  is  obtained  niv7  n'l  8 
ru  2.  But  the  assumed  quantity  n'l  7  ru  4  is  the  root  of  the  second  side  of 
equation,  and  equal  to  the  root  of  the  preceding  one  ya  1 .  Framing  an  equa- 
tion with  them,  the  number  is  found  by  the  former  process  n'l  7  ru  4,  with 
the  additive.'     It  comes  out  11.* 

'  See  §206. 
Putya  1.     Its  square,  less  thirty,  divided  by  seven,  yields  no  remainder  (§202).     Let  the 
quotient  be  ca.     This*  multiplied  by  seven  {ca  7)  is  equal  to  that  (j/a  r  1    ru  30).     (Statement  for 
equal  subtraction  3/a  V  1  ca  0  ru  30).   After  subtraction  there  remains  j/aip  1  Root  of  the  first 

yavO  ca  7  ruO  ca  7  ru  30 

side  is  ya  1 .  In  the  other  side,  by  rule  §  204, grading  the  absolute  30  by  the  divisor,  the  residue 
is  2  ;  to  which  add  a  multiple  of  the  divisor  (§  204),  viz.  twice  the  divisor,  the  sum  is  l6 ;  and  its 
square-root,  4. — Su'r.  and  Ram.  The  square  of  this  added  to  seven  nf  (n»  7  ru  4)  is  «/ r  49  ni56 
ru  l6 ;  equal  to  ca  7  ru  30.  Whence  the  value  of  ca  is  deduced  ni  v7  ni  S  ru  2. — Ram.  The 
assumed  quantity  ni7  ru  4  is  the  root  of  the  second  side  of  equation,  and  is  equal  to  the.  root  of 
the  first  3(al.     Whence  the  value  of  ya  is  found  nJ  7    ru  4,.  Sob.  and  Ra'm. 

'.  Putting  unity  for  ni.  Ram. 

*  Both  commentaries  have  '  sqnare  of  this :'  but  erroneously. 


VARIETIES    OF   QUADRATICS.  255 

If  seven  «?  were  put  with  a  negative  absolute  number,  a  different  result 
would  be  obtained. 

206.  Example  :*  Tell  me  what  is  the  number,  the  cube  of  which,  less  six, 
being  divided  by  five,  yields  no  residue  ?  if  thou  be  sufficiently  versed  in  the 
algebra^  of  cubes. 

Here  put  the  number  ya  1 .  Doing  with  it  as  directed,'  the  cube-root  of 
the  first  side  \%  ya  \;  and  the  other  side  is  c«  5  ru&;  from  which,  by  the  fore- 
going rule  (§  203 — 5)  adapted  to  cubes  (choosing  a  number  such  that  its  cube 
may  be  exactly  divisible  by  the  divisor,  as  well  as  its  multiple  into  thrice  the 
root  of  the  absolute  number;)  or  by  analogy,  making  it  equal  to  the  cube  of 
five  ni  with  six  absolute,  and  proceeding  as  before,  the  number  with  its  addi- 
tive is  found  n'l  5    ru  6.* 

207-  Example:'  If  thou  be  skilled  in  computation,  tell  me  the  number, 
the  square  of  which  being  multiplied  by  five,  having  three  added,  and  being 
divided  by  sixteen,  is  exhausted. 

Let  the  quantity  be  put  ya  1 .  Doing  with  this  as  said,  and  multiplying  both 
sides  of  equation  by  five,  the  square-root  of  the  first  side  is  ya  5.  In  the 
other  side  ca  80   ru  15,  retaining  the  divisor  as  enunciated,  and  taking  the 

'  An  instance  of  the  rule  (§  203 — 5)  applied  to  cubes. 
»  Cuiiaca. 

'  Put  ya  1.  Its  cube  less  six,  ya  gh  1  ru6,  being  divided  by  five,  is  exhausted.  Let  the  quo- 
tient   be    ca.       Multiplied    by    five   it*    is    equal    to    that.       Statement    for    equal   subtraction 

ya  gh  I    caO    ru6     After  subtraction,  the  root  of  the  first  side  is  ya  1. — Sua.  and  Ram.     In  the 
ya  gh  0   ca  5    ru  0 

other  side,  ca  5    ru  6,  by  rule  §  204,  abrading  the  absolute  number  6  by  the  divisor  5,   the  residue 

is  1  ;  to  which  add  a  multiple  of  the  divisor  (§  204):  forty-three  times  the  divisor   added  to  1  is 

2l6.     Its  cube-root  is  6.     Added   to   five  n.',  is  «/ 5    ru6.     The  cube  n<  gA  125    ni  viSO    n:  540 

ru2l6  is  equal  to  the  second  side  of  equation  r  a  5    ru6.     Whence  the  value  of  ca  is  found  without 

fraction   ni  gh  25    ni  v  90   nj  108    r«  42. — Ram.     The   assumed  quantity  ni  5    rw  6  is  cube-root 

of  the  second  side  of  equation  ca  5    ru6;  and  equal  to  the  rootof  the  first  side,  orj/a  1.     The  value 

of  ya  is  hence  deduced  niS    ru  6. — Su'r.  and  Ra'-vt. 

*  By  substitution  of  1  for  n/,  the  number  comes  out  11. — Su'r.  Putting  nought,  it  is  6;  orsup- 
posing  two,  it  is  l6. 

'  An  instance  of  the  rule  §  205.  Su'r. 

*  Both  the  commentaries  here  aUo  eshibit  "  cube  of  this."  Whether  by  error  of  tlie  authors  or  transcril>ers  may  be 
doubted. 

M   M 


266  Vl'JA-GAN'ITA.  Chapter  VII. 

absolute  number  as  it  is  adjusted  by  subtraction  (§  205),  the  result  is  cc  16 
ru  15.  Making  an  equation  of  this  with  eight  ni  and  unity,  the  value  ofca 
is  obtained  without  fraction,  ni  v  4  ni  1  rw  1.'  Equating  the  assumed  root 
ni  8  ru  I  with  the  root  of  the  first  side  ya  5,  the  value  of  i/a  is  found  by 
means  of  the  pulverizer,  pi  8  ru  5.  If  the  root  were  supposed  eight  ni  with 
negative  unity,  the  result  would  be  pi  8    ru  3.' 

'  It  is  five  times  too  great.  The  augmented  divisor  80  should  be  used  to  find  the  true  value  of 
the  quotient  ca. 

•  Put  yai.  Its  square,  multiplied  by  five  and  having  three  added,  is  yav  5  ru  3 ;  and  is  exactly 
divisible  by  sixteen.  Be  the  product  ca.  Multiplied  by  sixteen,  it*  is  equal  to  that.  After  equal 
subtractioHi  the  remainder  of  equation  is  ^  i>  5  Multiplying  both  sides  by  five,  (yo»  25         \ 

ca  l6    >-m3  ca  80  ru  15  J 

the  root  of  the  first  side  is  3^(j  5.  Of  the  other  side  (en  80  r«  15)  putting  the  enunciated  divisor 
sixteen  for  the  [coefficient  of]  colour  by  rule  §  205,  or  making  the  absolute  number,  as  it  is  altered 
by  subtraction  and  other  operations,  the  correct  absolute  (§  205);  the  statement  is  ca  l6  ru  15. 
Put  it  equal  to  the  square  ofeight«{  with  unity  (n/S  ru  l)t  the  statement  is  cd  0    ««r64    ni  16    r«  1 

CO  l6    nlvO     ni  0   ru  15 
Having  made  the  subtraction,  the  remainder  of  equation  is  »t  c  64    ni  l6  rul6;  and  divided  by 

CO  16 
the  divisor  (16)  niv  4,   ni  1    ru  1.  Su'ft.  and  Ram. 

The  assumed  root  ni  8   ru  1  is  equal  to  the  root  of  the  first  side  i/a5.     Statement  for  equal  sub- 
traction ya  0   ni  B    ru  1,     After  subtraction,  the  remainder  of  equation  is  n;  8    rul.     Proceeding 
ya  5    niO    ruO  ya  5 

by  the  rule  (§  101)  there  results  Dividend /ij  8  Additive  rul.     Then,   by  the  rule  (§  55),  there 

Divisor  3/a  5 

arises  an  uneven  series  -h  rn  -<  --  o  .  Multiplying  by  penult  and  so  on  (§  55)  the  pair  of  numbers 
deduced  is  w  <n  .  The  series  being  uneven,  the  quotient  and  multiplier  are  subtracted  from  their 
abraders  (§  57),  viz.  8  and  5.  Whence  the  quotient  and  multiplier  with  their  additives  are  ob- 
tained pi  8  ru  5.  The  quotient  is  the  value  oi ya  the  colour  of  the  divisor  (5  151),  and  the  multi- 
pi  5  ru  3 

plier  is  the  value  of  m  the  colour  of  the  dividend.    Statement  in  their  order,  pi  8  ru  5  value  oiya. 

pi  5  fuZ of  ni 

Or  let  the  assumption  be  eight  ni  with  unity  negative.  Statement  of  the  two  sides  of  equation 
ya  0  n«8  ru  1 ;  and  after  subtraction  ;;/  8  ru  1  ;  whence  Dividend  ni  8  Additive  ].  Then  by 
ya  5    «*  8   ru  0  ya  5  Divisor    ya  5 

*  T)ie«ame  error  again  occurs  in  both  commentaries,  which  here  pot  the  "  square."  It  occaaionallj  reappears  in  alt 
three  instances  in  course  of  the  operations  which  follow  :  still  however  leaving  it  doubtful  whether  it  be  not  imputable  to 
transcribers. 

t  The  root  ni  8  ru  1  is  rightly  assumed  conformably  wilh  the  rule  §  205.  For  15,  abraded  by  the  original  divisor  16, 
gives  a  residue  15,  to  which  adding  a  multiple  of  divisor  bv  one,  the  sum  (the  signs  being  contrary)  is  1 ;  and  its  square- 
root  1  is  to  be  used  as  root  of  ihc  absolute.  Tlie  coefficient  8  of  the  new  symbol  ni  is  duly  selected  such  that  its  square 
and  its  ninltipla  by  twice  that  root  of  the  absolute,  shall  both  be  divisible  by  16.  But  the  square  of  this  assumed  root  is 
not  equal  to  ca  16    ru  15,  but  to  ca  80   ru  15  and  to  xja  v  SS. 


VARIETIES    OF   QUADRATICS.  267 

The  scope  of  the  precept  '  many  different  ways  are  to  be  devised'  (§  173) 
has  been  thus  exhibited  in  a  multiplicity  of  instances.  Something  too  has 
been  shown  concerning  the  solution  of  quadratics  by  the  pulverizer.  Other 
devices,  as  practicable,  are  to  be  applied  by  intelligent  algebraists. 

the  rule  (§  55)  is  deduced  the  uneven  series  ^  _.  -,  -h  o  ,  and  from  this  the  pair  of  numbers  <n  e« . 

The  series  being  uneven,  but  the  additive  being  negative  (§  59),  they  are  quotient  and  multiplier : 

pis    rwS  value  of  j^a.     Substituting  with  pi  8    ru  5  for  value  of  j/a  1  (putting  unity  for  ^i)  it  is 
pi  5    ru2  of  ni 

13;  or  substituting  with  pi  8    ru3  it  is  11.  Ram. 


M  M  2 


CHAPTER    VIII 


EQUATION  INVOLVING  A  FACTUM  OF  UNKNOWN 

QUANTITIES. 

Next,  the  product  of  unknown'  is  propounded. 

208.  Rule :  two  half  stanzas.*^  Reserving  one  colour  selected,  let  values 
chosen  at  pleasure  be  put  for  the  rest  by  the  intelligent  algebraist.  So  will 
the  factum  be  resolved.  The  required  solution  may  be  then  completed  by 
the  first  method  of  analysis.' 

In  an  instance  where  a  factum  arises  from  the  multiplication  of  two  or 
more  colours  together,  reserving  one  colour  at  choice,  put  arbitrary  numeral 
values  for  the  rest,  whether  there  be  one,  two,  or  more.  Substituting  with 
those  assumed  values  for  the  colours  as  contained  in  the  sides  of  equation, 
and  adding  them  to  absolute  immber,  and  having  thus  broken  the  factum, 
find  the  value  of  the  [reserved]  colour  by  the  first  method  of  analytic  solution. 

209.  Example:  Tell  me,  if  thou  know,  two  numbers  such,  that  the  sum 
of  them,  multiplied  severally  by  four  and  by  three,  may,  when  added  to  two, 
be  equal  to  the  product  of  the  same  numbers. 

Let  the  numbers  he  it/a  \    cal.     Dealing  with  them  as  expressed,  the  two 

sides  of  equation  are  1/04-   ca  3    ru  2.     Thus  a  factum  being  raised,  let  an 

1/a.  ca  bh  1 

'  Bhdiila.     See  §  21  and  comment  upon  §  100. 

^  Compleiinga  stanza  begun  in  a  preceding  rule  (§  201)  and  beginning  auotbur  whicb  is  com- 
pleted in  the  following  (§  212). 

'  By  that  taught  under  the  head  of  simple  or  uniliteral  equation.     Ch.  4. 


EQUATION    INVOLVING   A    FACTUM.  26y 

arbitrary  value  be  put  for  ca,  under  the  rule  (§  208):  as,  for  instance,  five. 
Substituting  with  it  for  ca  in  the  first  side  of  equation,  and  adding  the  term 
to  the  absolute  number,  it  becomes ya  4  ru  \7  ;  and  the  other  side  becomes 
ya  5:  whence  by  like  subtraction,  as  before,  the  value  of  ya  is  obtained  17. 
Thus  the  two  numbers  are  17  and  5.  Or  substituting  six  for  ca,  the  two 
numbers  come  out  10  and  6.  In  like  manner,  by  means  of  various  supposi- 
tions, an  infinity  of  answers  may  be  obtained. 

210.  Example:  What  four  numbers  are  such,  that  the  product  of  them 
all  is  equal  to  twenty  times  their  sum  ?  say,  learned  algebraist,  who  art  con- 
versant with  the  topic  of  product  of  unknown  quantities. 

Here  let  the  first  number  hei/a  I ;  and  the  rest  be  arbitrarily  put  5,  4  and  'J. 
Their  sum  is  j/a  1  rw  II.  Multiplied  by  twenty,  ^/a 20  ?•«  220.  Product 
of  all  the  quantities  ya  40.     Statement  for  equation  ya  40    ?-m  0      Hence  by 

ya  20    ru  220 
the  first  analysis,  the  value  of  ya  is  found  1 1 ;  and  the  numbers  are  11,  5,  4 
and  2.     Or  [with  a  different  supposition]  they  are  55,  6,  4  and  1 ;  or  60,  8,  3 
and  1 ;  or  28,  10,  2  and  1,     In  like  manner  a  multiplicity  may  be  found. 

211.  Example:  Say  what  is  the  pair  of  numbers,  of  which  the  sum,  the 
product  and  both  squares  being  added  together,  the  square-root  of  the  aggre- 
gate, together  with  the  pair  of  numbers,  may  amount  to  twenty-three?  or  else 
to  fifty-three?  Tell  them  severally;  and  in  whole  numbers.  If  thou  know 
this,  thou  hast  not  thy  e(jual  upon  earth  for  a  good  mathematician. 

In  this  case,  let  the  numbers  be  \mt  ya  1  ru  2.  The  aggregate  of  their 
product,  sum  and  squares,  is  yav  1  ya3  ru6.  It  is  equal  to  the  square  of 
twenty-three  less  the  sum  of  the  numbers  (j/a  1  rw  21),  viz.  ya  v  I  yaik 
rw  441.  From  this  equation  the  value  of  ^«  is  obtained  V  5  and  thus  the  two 
numbers  are  V  ^^^'^  ^' 

Or  else  let  the  numbers  be  supposed  ya  I,  ru  3.  Proceeding  as  before, 
the  two  numbers  are  thence  found  j-{  and  3.  In  like  manner  putting  five 
for  the  assumed  quantity:  the  two  come  out  in  whole  numbers  7  and  5. 

In  the  second  example,  put  the  quantities  ya  1  ru  2.  The  aggregate  of 
their  product,  sum  and  squares  hya  v  I  ya  3  ru6.  It  is  equal  to  the  square 
of  fifty-three,  less  the  sum  of  the  numbers  (ya  1  ru  51)  viz.  yav  I  ya  KJa 
7'm2601.  From  the  equation  of  these,  by  the  foregoing  process,  the  two 
numbers  are  ^^  and  |.     Or  integers  they  are  1 1  and  1 7. 


f70  VI'JA-GAN'ITA.  Chapter  VIII. 

Thus,  one  quantity  being  put  an  absolute  number,  the  other  is  brought 
out  au  integer  witii  much  trouble.  How  it  may  be  clone  with  little  labour, 
is  next  shown. 

212 — 214.  Rule:  two  and  a  half  stanzas.  Removing  the  factum  from  one 
side,  and  the  simple  colours  and  absolute  number  from  the  other,  as  optionally 
selected,  and  dividing  both  sides  of  the  equation  by  the  coefficient  of  the 
factum,  divide  the  sum  of  the  product  of  the  coefficients  of  the  colours  added 
to  the  absolute  number  by  any  assumed  number;  the  quotient  and  the  num- 
ber assumed  must  be  added  to  the  coefficients  of  the  colours,  at  choice;  or 
be  subtracted  from  them:  the  sums,  or  the  differences,  will  be  the  values  of 
the  colours:  and  they  must  be  understood  to  be  so  reciprocally.' 

Removing  by  subtraction  the  factum  from  one  of  the  equal  sides,  and  the 
simple  colours  and  absolute  number  from  the  other,  and  then  reducing  the 
two  sides  to  the  lowest  denomination,  by  the  coefficient  of  the  factum  as 
common  measure,  and  dividing  by  some  arbitrarily  assumed  number  the  pro- 
duct of  the  coefficients  of  the  colours  on  the  second  side  added  to  the  abso- 
lute number,  the  assumed  quantity  and  the  quotient,  having  the  coefficients 
of  the  two  colours  added  to  them  respectively,  as  selected  at  pleasure,  are 
values  of  the  colours ;  and  to  Ik;  so  understood  reciprocally  :  that  is,  the  one, 
to  which  the  coefficient  of  ca  is  annexed,  is  the  value  of  j/a ;  and  that,  to 
which  the  coefficient  ofj/a  is  added,  is  the  value  of  ca.  But,  if,  owing  to  the 
magnitude,  the  condition  be  not  answered,  when  that  has  been  done,  the 
coefficients,  less  the  quotient  and  assumed  number,  are  the  values  recipro- 
cally. 

First  Example :  "  Tell  two  numbers  such,  that  the  sum  of  them,  multi- 
plied by  four  and  three,  may,  added  to  tw  o,  be  equal  to  the  product"  (§  209). 

Here,  that  which  is  directed,  being  done,  the  two  sides  of  equation  are 
^a4    ca3    ru  2."     The  sum  of  the  product  of  the  coefficients  with  absolute 

ya.  cabhl 
number  is  14.     This,  divided  by  one  put  as  the  assumed  number,  gives  1  and 
14  for  assumed  number  and  quotient.     These,  with  the  two  coefficients  re- 

'  See  BttAHMECUPTA  18,  §36;  which  appears  from  a  subsequent  passage  (ibid.  §  38)  and  the 
scholiast's  remark  on  il,  to  be  a  rule  borrowed  from  a  still  earlier  writer. 

*  The  subtraction  (or  transposition)  and  division  by  the  coefficient  (which,  in  the  instance,  is 
unity,)  leaves  the  equation  unaltered.  •  Sua. 


EQUATION   INVOLVING    A   FACTUM.  271 

spcctively  added,  taking  them  at  choice,  furnish  tlie  vakies  of  ya  and  ca, 
cither  4  and  1 8,  or  17  and  5.  By  the  supposition  of  two,  they  come  out  5  and 
11;  or  10  and  6. 

The  demonstration  follows.  It  is  twofold  in  every  case:  one  geometrical, 
the  other  algebraic'  The  geometric  demonstration  is  here  delivered.  The 
second  side  of  the  equation  is  equal  to  the  factum  of  the  quantities.  But  that 
factum  is  the  area  of  an  oblong  quadrangular  figure.*  The  two  colours  are 
its  side  and  upright.       cat         Within  that  plain  figure  is  contained  four  times 


ya  with  thrice  ca  and  twice  unity.  Within  this  figure,  then,  four  times  j/a 
being  taken  away,  as  also  ca  less  four,  multiplied  by  its  own  coefficient,  it 
becomes    *  And  the  second  side  of  the  equation  being  so  treated, 


ya 


ca 

there  results  ru  14.  This  is  the  area  of  the  remaining  rectangle  at  the  cor- 
ner, within  the  rectangle  representing  the  factum  of  the  quantities.  It  is  a 
product  arising  from  the  multiplication  of  a  side  and  upright.  But  they  are 
here  unknown.  Therefore  an  assumed  number  is  put  for  the  side;  and  if 
the  area  be  divided  by  that,  the  quotient  is  the  upright.  Either  of  the  two 
(side,  or  upright,)  with  the  addition  of  a  number  equal  to  the  coefficient  of 
■ya,  is  the  upright  of  the  rectangle  representing  the  factum;  because  that  up- 
right was  lessened  by  it  when  four  times  ^«  was  taken  from  the  rectangle 
representing  the  factum.  In  like  manner,  the  other,  Avith  the  addition  of  a 
number  equal  to  the  coefficient  o?  ca,  is  the  side.  These  precisely  are  values 
oi  ya  and  ca. 

The  algebraic  demonstration  is  next  set  forth.  That  also  is  grounded  on 
figure.  Let  other  colours,  ni  1  and  pi  1,  be  put  for  the  length  of  the  side 
and  upright  in  the  smaller  rectangle  within  the  larger  one,  which  consists 
of  a  side  and  upright  represented  by  ya  and  ca.  Then  either  of  them,  added 
to  a  number  equal  to  the  coefficient  oi ya,  is  the  value  o? ya  the  side  of  that 
rectangle  :  viz.  nil  rwi  and  pi  1  ru  3.  Substituting  with  these  for  ca  and 
ya  in  both  sides  of  the  equation,  the  upper  side  of  it  becomes  pi  4  ni  3  ru  26 ; 

Cshefra-gata,  geomeiuc  :  R(f«-g:a<(J,  algebraic  or  arithmetical.     ('far«'a-^a/(f,  algebraic  exclii- 
kively.) 

*  Ai/ata-chaturasra.     See  Ltl.  Ch.  6. 


272 


Vl'JA-G  ANITA. 


Chapter  VIII. 


and  that  containing  tlic  factum  is  transformed  into  tii.  pi  bh  1  in  3  pi  A  ru  12. 
Like  subtraction  being  made,  the  lower  side  of  equation  is  ni.pibh  1  ;  and 
the  upper  side  is  ru  14.  It  is  the  area  of  that  inner  rectangle;  and  it  is 
equal  to  the  product  of  the  coefficient  added  to  the  absolute  number.*  How 
values  of  the  colours  are  thence  deduced,  has  heen  already  shown. 

This  very  operation  has  been  delivered,  in  a  compendious  form,  by  ancient 
teachers.  The  algebraic  demonstration  must  be  exliibited  to  those  who  do 
not  comprehend  the  geometric  one. 

'  Mathematicians  have  declared  algebra  to  be  computation  joined  with  de- 
monstration :  else  there  would  be  no  difference  between  arithmetic  and 
algebra.' 

Therefore  this  explanation  of  the  principle  of  the  resolution  has  been 
shown  in  two  several  ways. 

It  has  been  said  above,  that  the  product  of  the  coefficient,  added  to  the 
absolute  number,  is  the  area  of  another  small  rectangle  within  that  which 
represents  the  factum  of  the  unknown,  and  situated  at  its  corner.  Some- 
times, however,  it  is  otherwise.  When  the  coefficients  are  negative,  the 
rectangle  representing  the  factum  will  be  within  the  other  at  its  corner. 
When  the  coefficients  are  greater  than  the  side  and  upright  of  the  rectangle 
representing  the  factum,  and  are  affirmative,  the  new  rectangle  will  stand 
without  that  which  represents  the  factum,  and  at  its  corner.     See 

3     CO  40 


ya 
5 


When  it  is  so,  the  coefficients,  lessened  by  subtraction  of  the  assumed  num- 
ber and  quotient,  are  values  of  ya  and  ca. 

215.  Example:  What  two  numbers  are  there,  twice  the  product  of 
which  is  equal  to  fifty-eight  less  than  the  sum  of  their  multiples  by  ten  and 
fourteen? 

Let  the  two  numbers  be  put  ya\,  ca\.     What  is  directed  being  done 


♦  4x3  +  2  =  14. 


EQUATION    INVOLVING    A    FACTUM.  273 

with  them,  and  the  equation  being  divided  by  the  coefficient  of  the  factum, 

the  result  is  ya5   ca7    ru  29     The  sum  of  tlie  product  of  coefficients  with 

ya.  ca  bh  1 
the  absolute  number,  viz.  6*  is  divided  by  two ;  and  the  assumed  number 
and  quotient  are  2  and  3.     The  coefficients  with  these  added  are  either  10 
and  7,  or  9  and  8  ;  and,  with  the  same  subtracted,  are  4  and  3,  or  5  and  2: 
the  numbers  required. 

216.  Example:  What  two  numbers  are  there,  the  product  of  which, 
added  to  triple  and  quintuple  the  numbers  themselves,  amounts  to  sixty- 
two?     Tell  them,  if  thou  know. 

Here  also,  what  is  expressed  being  done,  there  results  yaS    ca5    ru  62 

ya.  ca  bha  1 

The  sum  of  the  product  of  coefficients  with  absolute  number  is  77- 1     The 

assumed  number  and   quotient,   7  and   11.     The  coefficients,    with    these 

added,  make  the  numbers  6  and  4,  or  2  and  8.     They  should  be  added  only, 

as  the  numbers  come  out  negative,  if  they  be  subtracted.' 

The  foregoing  third  and  fourth  examples :  "  What  is  the  pair  of  numbers, 
&c."C§211.) 

Put  the  two  numbers  ya\,  ca  1.  The  aggregate  of  their  product,  sum 
and  squares,  is  ^a  i;  1  cav  \  ya.  ca  bh  1  ya  \  ca  \.  Since  this  does  not 
affiard  a  square-root,  equal  it  with  the  square  of  twenty-three  less  the  two 
quantities  {ya\  ca\  ru^S)  \\z.yav\  cav\  ya.cabh2  ya4:6  ca46  ru59,9. 
Dropping  the  equal  squares,  and  subtraction  being  made,  the  remaining 
equation  divided  by  the  coefficient  of  the  factum  of  the  unknown  (viz. 
unity*)  gives  ya  47  ca  47  ru  .529.  The  product  of  the  coefficients  added  to 
the  absolute  number  is  1680 ;'  and  this,  being  divided  by  forty  as  assumed 
number,  gives  quotient  and  arbitrary  number  42  and  40.  Here  the  quotient 
and  arbitrary  assumed  number  must  only  be  subtracted  from  the  coefficients; 

♦  (5x7)— 29=6. 

+  (— 3x— 5)+62=77. 

'  The  coefficients,  with  the  arbitrar}'  assumed  number  and  quotient  subtracted,  make  12  and  1*, 
«r  16  and  20.  Ram. 

♦  The  equal  squares  being  dropped,  the  statement  for  subtraction  is  ya.  CO  6A  1  ya    1  ca    1 

ya,  ca  bh  2  ya  46  ca  4o  ru  5^8 
After  subtraction  ya  47    ca  47    ru  529 

ya.  ca  bh  1  Ram. 

»  2209-529. 

V  N 


874  VI'JA-GAN'ITA.  Chapter  VIII. 

and  the  numbers  will  thus  come  out  7  and  5.  If  they  were  added,  the  con- 
dition, that  they  shall  amount  to  twenty-three  (§211),  would  not  be  ful- 
filled.' 

"  Or  else  amount  to  fifty -three"  (§  211).  In  this  example,  that  which  has 
been  directed  being  done,  there  arises  ya\07  ca\07  rw  2809.  Here  the 
sum  of  the  product  of  coefficients  with  the  absolute  number  is  8640.  The 
arbitrary  number  and  quotient  90  and  9^.  The  coefficients  less  these  quan- 
tities are  the  numbers  required,  1 1  and  17. 

So,  likewise,  in  other  instances. 

In  some  cases,  where  the  equations  are  numerous,  finding  various  values 
of  the  factum  of  unknown  quantities,  and  with  those  values  equated  and 
reduced  to  a  common  denomination,  the  two  quantities  may  be  discovered 
from  the  equation,  by  the  former  process  of  analytic  solution. 

From  the  mention  of  quantities  in  the  dual  number,  it  is  evident  of  course, 
that  arbitrary  values  are  to  be  put  for  the  rest  of  the  colours,  in  the  cases  of 
three  or  more. 

•  By  addition,  the  numbers  are  87  and  89.  The  square-root  of  the  aggregate  (23402)  is  155. 
The  pair  of  numbers  added  together,  176.     If  the  root  be  taken  negative,  the  amount  is  23.    Sua. 


CHAPTER    IX. 


¥ 


CONCLUSION. 

&\7.  On  earth  was  one  named  Mahe's'wara,  who  followed  the  eminent 
path  of  a  holy  teacher  among  the  learned.  His  son,  Bhascaua,  having 
from  him  derived  the  bud  of  knowledge,  has  composed  this  brief  treatise  of 
elemental  computation/ 

£18.  As  the  treatises  of  algebra  by  Brahmegupta,"  Siiid'haua  and 
Padmanabha  are  too  diffusive,  he  has  compressed  the  substance  of  them  in 
a  well  reasoned  compendium,  for  the  gratification  of  learners. 

219 — 223.  For  the  volume  contains  a  thousand  lines'  including  precept 
and  example.  Sometimes  exemplified  to  explain  the  sense  and  bearing  of  a 
rule ;  sometimes  to  illustrate  its  scope  and  adaptation :  one  while  to  show 
variety  of  inferences ;  another  while  to  manifest  the  principle.     For  there 

'  Laghu  Vija-gariita. 

*  The  text  expresses  Brahmihwaya-vija,  algebra  named  from  Brahma ;  alluding  to  the  name  of 
Brahmegupta,  or  to  the  title  of  his  work  Brahmesidd'hinta,  of  which  the  18th  chapter  treats  of 
algebra.  The  commentator  accordingly  premises  '  Since  there  are  treatises  on  algebra  by  Bra  h- 
MEGUPTA  and  the  rest,  what  occasion  is  there  for  this  f  The  author  replies  "  As  the  treatises, 
&c."  Ram. 

'  Anushtubh.  Lines  of  thirty-two  syllables,  like  the  metre  termed  anushtubh.  This  intimation  of 
the  size  of  the  volume  regards  both  the  prose  and  metrical  part.  The  number  of  stanzas  including 
rules  and  examples  is  210;  or,  with  the  peroration,  219-  Some  of  the  rules,  being  divided  by  in- 
tervening examples  in  a  different  metre,  have  in  the  translation  separate  numbers  affixed  to  the 
divisions.  On  the  other  hand  a  few  maxims,  and  some  quotations  in  verse,  have  been  left  un- 
Bumbered. 

N  n2 


876  VI'JA-GAN'ITA.  Chapter  IX. 

is  no  end  of  instances  :  and  therefore  a  few  only  are  exhibited.  Since  the 
wide  ocean  of  science  is  difficultly  traversed  by  men  of  little  understanding: 
and,  on  the  other  hand,  the  intelligent  have  no  occasion  for  copious  instruc- 
tion. A  particle  of  tuition  conveys  science  to  a  comprehensive  mind  ;  and 
having  reached  it,  expands  of  its  own  impulse.  As  oil  poured  upon  water, 
as  a  secret  entrusted  to  the  vile,  as  alms  bestowed  upon  the  worthy,  how- 
ever little,  so  does  science  infused  into  a  wise  mind  spread  by  intrinsic 
force. 

It  is  apparent  to  men  of  clear  understanding,  that  the  rule  of  three  terms 
constitutes  arithmetic  ;  and  sagacity,  algebra.  Accordingly  I  have  said  in 
the  chapter  on  Spherics :' 

224.  '  The  rule  of  three  terras  is  arithmetic ;  spotless  understanding  is 
algebra.*  What  is  there  unknown  to  the  intelligent  ?  Therefore,  for  the 
dull  alone,  it'  is  set  forth.' 

225.  To  augment  wisdom  and  strengthen  confidence,  read,  do  read,  ma- 
thematician, this  abridgment  elegant  in  stile,  easily  understood  by  youth, 
comprising  the  whole  essence  of  computation,  and  containing  the  demon- 
stration of  its  principles,  replete  with  excellence  and  void  of  defect. 

'  GolM'hy&ya.     Sect.  II.  §  3. 

^  V'ija. 

'  The  solution  of  certain  problems  set  forth  in  the  section*  The  preceding  stanza,  a  part  o£ 
which  is  cited  by  the  scholiast  of  the  Lildvati,  (Ch.  12),  premises,  '  I  deliver  for  the  instruction  of 
youth  a  few  answers  of  problems  found  by  arithmetic,  algebra,  the  pulverizer,  the  affected  square, 
the  sphere,  and  [astronomical]  instruments.'    G61,  Sect.  II.  §2. 


GANITAD HYA YA,  ON  ARITHMETIC; 

THE  TWELFTH  CHAPTER  OF  THE 

BRAHME-SPHUTA-SIDD'HANTA, 
BY  BRAHMEGUPTA; 

WITH  SELECTIONS  FROM  THE  COMMENTARY  ENTITLED 

VASA  NA-BHASHYA, 
BY  CHATURVEDA-PRIT'HUDACA-SWAMI. 


CHAPTER    XII. 

ARITHMETIC. 


SECTION  I. 

1.  He,  who  distinctly  and  severally  knows  addition  and  the  rest  of  the 
twenty  logistics,  and  the  eight  determinations  including  measurement  by 
shadow,'  is  a  mathematician. - 

2.  Quantities,  as  well  numerators  as  denominators,  being  multiplied  by 

.  '  Addition,  subtraction,  multiplication,  division,  square,  square-root,  cube,  cube-root,  five 
[should  be,  sIn]  rules  of  reduction  of  fractions,  rule  of  three  terms  [direct  and  inverse,]  of  five 
terras,  seven  terms,  nine  terms,  eleven  terms,  and  barter,  are  twenty  (paricarmanj  arithmetical 
operations.  Mixture,  progression,  plane  figure,  excavation,  stack,  saw,  mound,  and  shadow,  are 
eight  determinations  (vyavah&ra) .  Ch. 

For  topics  of  Algebra,  see  note  on  §  66. 

*  Gadaca,  a  calculator ;  a  proficient  competent  to  the  study  of  the  sphere.  Ch. 


278  BRAHMEGUPTA.  Chapter  XII. 

the  opposite  denominator,  are  reduced  to  a  common  denomination.  In 
addition,  the  numerators  are  to  be  united.'  In  subtraction,  their  difference 
is  to  be  taken.' 

3.  Integers  are  multiplied  by  the  denominators  and  have  the  numerators 
added.  The  product  of  the  numerators,  divided  by  the  product  of  the  deno- 
minators, is  multiplication"  of  two  or  of  many  terms.* 

4.  Both  terms  being  rendered  homogeneous,'  the  denominator  and  nu- 

•  Scanda-se'k-a'cha'rya,  who  has  exhibited  addition  by  a  rule  for  the  summation  of  series  of 
the  arithraeticals,  has  done  so  to  show  the  figure  of  sums ;  and  he  has  separately  treated  of  figu- 
rate  quantity  (cshetra-r6si),  to  show  the  area  of  such  figure  in  an  oblong.  But,  in  this  work, 
addition  being  the  subject,  sum  is  taught;  and  the  author  will  teach  its  figure  by  a  rule  for  the 
summation  of  series  (§  19)-  In  this  place,  however,  sum  and  difference  of  quantities  haying  like 
denominators  are  shown:  and  that  is  fit.  Cti. 

*  Example  of  addition  :*  What  is  the  sum  of  one  and  a  thirdi  one  and  a  half,  one  and  a  sixth 
part,  and  the  integer  three,  added  together? 

Sutement:   lA  1^  1^  3.     Or  reduced  J  f  J  f . 

The  numerator  and  denominator  of  the  first  term  being  multiplied  by  the  denominator  of  the 
second,  2,  and  those  of  the  second  by  that  of  the  first,  3,  they  are  reduced  to  the  same  denominator 
(?  f ;  ^"^>  uniting  the  numerators,  y).  With  the  third  term  no  such  operation  can  be,  since  the 
denominator  is  the  same:  union  of  the  numerators  is  alone  to  be  made;  ^,  which  abridged  is)  4. 
So  with  the  fourth  term:  and  the  addition  being  completed,  the  sum  is  7. 

Subtraction  is  to  be  performed  in  a  similar  manner;  and  the  converse  of  the  same  example  may 
serve.  Ch. 

'  Pra<3^ui'j)an«a,  product  of  two  proposed  quantities.— Ch.  See  a  rule  of  long  multiplication, 
§55. 

♦  Example :  Say  quickly  what  is  the  area  of  an  oblong,  in  which  the  side  is  ten  and  a  half,  and 
the  upright  seventy  sixths. 

Statement:  10|  11|.  Multiplying  the  integers  by  the  denominators,  adding  the  numerators, 
and  abridging,  the  two  quantities  become  ^  and  ^.  From  the  product  of  the  numerators  735, 
divided  by  the  product  of  the  denominators  6,  the  quotient  obtained  is  122  i.  It  is  the  area  of 
the  oblong. 

Others  here  exhibit  an  example  of  the  rule  of  three  terras,  making  unity  stand  for  the  argument 
or  first  terra.  For  instance,  if  one  pah  of  pepper  be  bought  for  six  and  a  half  paiias,  what  is  the 
price  of  twenty-six  pato?     Answer:  i6d  paiias.]  Cii. 

'  The  method  of  rendering  homogeneous  has  been  delivered  in  the  foregoing  rule  (|  3)  "  Integers 
are  multiplied  by  the  denominators,"  &c. — Ch,  It  is  reduction  to  the  form  of  an  improper 
fraction. 

•  It  is  not  quite  clear  wlietlier  the  examples  are  the  autlior's  or  the  commentator's.  The  metre  of  them  is  different  from 
that  of  the  rules;  and  they  are  not  comprehended,  either  in  this  or  in  the  chapter  on  Algebra,  in  the  summed  contents  at 
tlie  close  of  each.    They  are  probably  the  commentator's ;  and  consigned  therefore  to  the  notes. 


Section  I.  LOGISTICS:    FRACTIONS.  279 

merator  of  the  divisor  are  transposed  :  and  then  the  denominator  of  the  di- 
vidend is  multiplied  by  the  [new]  denominator;  and  its  numerator,  by  the 
[new]  numerator.     Thus  division'  [is  performed.] 

5.  The  quantity  being  made  homogeneous,*  the  square  of  the  nume- 
rator, divided  by  the  square  of  the  denominator,  is  the  square.'  The  root 
of  the  homogeneous  numerator,  divided  by  the  root  of  the  denominator,  is 
the  square-root.* 

6.  The  cube  of  the  last  term  is  to  be  set  down;  and,  at  the  first  remove 
from  it,  thrice  the  square  of  the  last  multiplied  by  the  preceding;  tlien 
thrice  the  square  of  this  preceding  term  taken  into  that  last  one;  and  finally 
the  cube  of  the  preceding  term.     The  sum  is  the  cube.' 

'  Example :  In  a  rectangle,  the  area  of  which  is  given,  a  hundred  and  twenty-two  and  a  half; 
and  the  side,  ten  and  a  half;  tell  the  upright. 

Statement:     122^  10^.     Reduced  to  homogeneous  form  2|5    ^, 

Here  the  side  is  divisor.  Its  denominator  and  numerator  are  transposed  ^.  The  numerator  of 
the  dividend,  multiplied  by  this  numerator,  becomes  490 ;  and  the  denominator  of  the  dividend, 
taken  into  the  denominator,  makes  42.  The  one,  divided  by  the  other,  gives  the  quotient  11  j. 
It  is  the  upright. 

Some  in  this  place  also  introduce  an  example  of  the  rule  of  three  terms.  Thus  "  A  king  gave 
to  ten  principal  priests  a  hundred  thousand  pieces  of  money,  together  with  a  third  of  one  piece. 
What  was  the  wealth  that  accrued  to  one?"  Ch. 

*  As  before. — Ch.     [That  is,  reduced  to  fractional  form.] 

Put  unity  as  the  denominator  of  an  integer ;  and  proceed  as  directed.  Ch. 

'  A  square  is  the  product  of  two  like  quantities  multiplied  together.  §  62.  The  present  rule  is 
introduced  to  show  how  the  square  of  a  fraction  is  found.  Ch. 

Example :  Tell  the  area  of  an  equilateral  tetragon,  the  side  and  upright  of  which  are  alike 
seven  halves. 

Statement:  Side  J  Upright -1.  Product  of  the  numerators  49.  Product  of  the  denomina- 
tors 4.     These  products  are  squares,  since  the  side  and  upright  are  equal. 

The  square  of  the  numerator  49  being  divided  by  the  square  of  the  denominator  4,  the  quotient 
12  ^  is  the  area  of  the  tetragon.  lli. 

*  Example  :  Tell  the  equal  side  and  upriglit  of  an  equilateral  tetragon,  the  area  of  which  is 
determined  to  be  twelve  and  a  quarter. 

Statement,  after  rendering  homogeneous  :  *^.  The  root  of  the  homogeneous  numerator  49,  is 
7  :  that  of  the  denominator  4,  is  2.  Dividing  by  this  the  root  of  the  numerator,  the  quotient  is 
the  square-root  |.     It  is  the  length  of  the  upright  and  of  the  side.  Ch. 

'  Continued  multiplication  of  three  like  quantities  is  a  cube.  §  62.  As  1,  8,  27,  64,  125,  2l6, 
343,  512,  729,  cubes  of  numbers  from  1  to  9.    The  rule  is  introduced  for  finding  the  cube  of  ten 


380  BRAH  ME  GUPTA.  Chapter  XII. 

7.  The  divisor  for  the  second  non-cubic  [digit]  is  thrice  the  square  of  the 
cubic-root.  The  square  of  the  quotient,  niultiphed  by  three  and  by  the  pre- 
ceding, must  be  subtracted  from  the  next  [non-cubic];  and  the  cube  from 
the  cubic  [digit]:  the  root  [is  found].' 

and  so  forth.  The  cube  of  any  given  quantity  comprisingiwo  or  more  digits  or  terms  is  required. 
The  cube  of  the  last  digit,  found  by  continued  multiplication,  is  to  be  set  down.  Then  the  square 
of  that  last  digit,  tripled  and  multiplied  by  the  term  next  before  the  last,  is  to  be  set  down,  at  one 
remove  or  place  of  figures  from  that  of  the  cube  previously  noted  ;  and  to  be  added  to  it.  [So  the 
square  of  this  term  tripled  and  taken  into  the  last  digit.]  Then  the  cube  of  the  term  so  preceding 
is  set  down  in  the  next  place  of  figures;  and  added.  Thus  the  cube  of  two  terms  or  digits  is  found. 
For  a  number  comprising  three  or  more  terms,  put  two  of  them  [previously  finding  the  cube  of  this 
binomial  by  the  rule]  for  last  term  ;  and  proceed  in  every  other  respect  conformably  with  the  di- 
rections; and  then,  in  like  manner,  put  the  trinomial*  for  last  term  ;  and  so  on,  to  find  the  cube  of 
a  quantity  containing  any  number  of  terms.  Ch. 

Example  :  Tell  the  cubic  content  of  a  quadrangular  equilateral  well  (or  cistern)  measured  by 
three  cubits  cubed  and  the  same  in  depth. 

Statement:  27,  27,  27.  The  product  of  these  three  equal  quantities  is  19683.  It  is  the  con- 
tent in  cubits  of  a  solid  having  twelve  corners  :t  for  "  the  multiplication  of  three  like  quantities  is 
a  twelve-angled  solid." 

The  rule  furnishes  another  method.  The  cube  of  twenty-seven  is  required.  The  cube  of  the 
last  digit  2  is  set  down  8.  The  square  of  the  last  8,  tripled,  is  12,  and  multiplied  by  the  preceding 
is  84:  set  down  at  the  first  remove,  and  added  to  the  cube  previously  noted,  it  makes  l64,  [Thrice 
the  square  of  7  multiplied  by  2  is  2f)4;  put  at  the  next  place  of  digits  and  added,  makes  1934.] 
Cube  of  the  preceding  digit  7  is  343.  Added  as  before,  it  gives  19683.  It  is  the  solid  content  in 
cubits  ;  that  is,  it  contains  so  many  twelve-angled  excavations  measured  by  a  cubit. 

The  same  is  to  be  understood  of  a  pile  or  stack  ;  putting  height  instead  of  depth.  Ca. 

'  The  first  digit  of  the  proposed  cube  is  termed  cubic  ;  and  proceeding  inversely,  the  two  next 
places  of  figures  are  denominated  non-cubic;  then  one  cubic,  and  two  non-cubic;  and  so  on  alter- 
nately, until  the  end  of  the  number.     With  this  preparation,  the  rule  takes  effect The 

meaning  is  as  follows :  In  the  first  place,  the  cube  of  some  number  is  to  be  subtracted  from  the 
lastof  all  the  digits  termed  cubic;  and  that  number  is  reserved,  and  set  down  apart  with  the  designa- 
tion of  cube-root.  Take  its  square  and  multiply  this  by  three ;  and  with  the  tripled  square 
divide  the  digit  standing  next  before  that  of  which  the  cube-root  was  taken  ;  and  note  the  quotient 
ill  the  second  place  contiguous  in  direct  order  to  the  reserved  cube-root.  Square  the  quotient, 
and  multiply  by  three  and  by  the  cube-root  first  found ;  and  subtract  the  product  from  the  first 
non-cubic  standing  before  that  of  which  the  division  was  made.  Then  taking  the  cube  of  the 
quotient  subtract  it  from  the  next  preceding  cubic  digit.  Thus  a  binomial  root  is  found.  If  more 
be  requisite,  put  the  binomial  root  for  first  term  ;  and  proceed  in  every  respect  according  to  the 
rule,  using  it  as  first  cube-root:  and  then  put  the  trinomial,  and  afterwards  the  tetranomial,  for 
first  radical  term  ;  until  the  proposed  number  be  exhausted. 

*  Vwipada,  binomial;  tripada,  U'luomialj  chatushpadaiteUanomitiU 

t  Duddiudiri,  lit.  dodecagon  ;  but  iiilendiiig  a  rube  or  a  parallelopipedon.    See  LiUttati,  i  7. 


c 


Suction  I.  LOGISTICS:    FRACTIONS.  281 

8.  The  sum  of  numerators  which  have  like  denominators,  being  divided 
by  the  [common]  denominator,  is  the  result  in  the  first  reduction  to  homo- 
geneousness :'  in  the  second,  multiply  numerators  by  numerators,  ^nd  deno- 
minators by  denominators.'' 

Example  :  Tell  the  cubic-root  of  a  stack,  of  which  the  flanks*  and  elevation  are  alike,  and  the 
solid  content  is  equal  to  twelve  thousand,  one  hundred  and  sixty-seven. 

Statement:  121 67.  Here  the  digit  7  is  named  cubic  ;  6  and  1  non-cubic;  2  cubic.  From  that 
subtract  the  cube  of  two,  the  remainder  is  4l67.  Cube-root  2;  its  square  4;  tripled  12;  this  is 
the  divisor.  Dividing  by  that  the  second  non-cubic  digit,  the  quotietit  is  3  and  remainder  567. 
The  square  of  the  quotient  9 ;  multiplied  by  three,  27,  and  by  the  preceding,  54.  Subtracted 
from  the  first  non-cubic,  the  residue  is  27-  Cube  of  the  quotient,  27,  subtracted  from  the  cubic 
place  of  figures,  leaves  no  remainder.  Thus  the  root  is  this  binomial  23.  So  much  is  the  height; 
as  much  the  length ;  and  as  much  the  breadth  of  the  pile. 

For  trinomials  and  the  rest,  proceed  as  directed. 

Such  is  the  method  of  finding  the  cube  and  cube-root  of  integers.  For  the  cube  of  fractions,  let 
the  cube  of  the  numerator,  after  the  quantity  has  been  rendered  homogeneous  [§3],  and  the  cube 
of  the  denominator,  be  separately  computed  :  and  divide  the  one  by  the  other,  the  quotient  is  the 
cube  sought.  For  the  cube-root,  let  the  roots  be  separately  extracted,  and  then  divide  the  cube- 
root  of  the  numerator  by  that  of  the  denominator,  the  quotient  is  the  cube-root  of  the  fraction.  Ch. 

'  The  author  here  teaches  the  method  of  finding  the  result  of  the  first  assimilation  Cjdti)  con- 
sisting in  addition.  The  sum  of  numerators  which  have  dissimilar  denominators  is  never  taken. 
All  the  quantities  must  be  reduced  to  like  denominators :  and  then  the  addition  of  numerators  is 
made  ;  and  the  sum  is  divided  by  a  single  common  denominator. 

Example  :  Half  of  unity,  a  sixth  part  of  the  same,  a  twelfth  part  of  it,  and  a  quarter,  being  added 
together,  what  is  the  amount  ? 

Statement :  i  ^  tV  -J.  Reduced  to  like  denominators  the  numerators  become  -^  ^V  t^i  A- 
Added  together  and  divided  by  the  numerator,  the  result  is  unity. 

Example:  Twenty-two,  sixty-six,  thirty-eight,  thirty-nine,  thirteen,  a  hundred  and  fourteen  are 
put  in  the  denominator's  place,  and  five,  seven,  nine,  one,  four  and  eleven  are  their  numerators. 
When  they  are  added  together  what  is  the  whole  sum? 

Statement :  ^2  jV  ^s  A  "A  t¥i-     Answer :  one. 
But  when  the  similar  denomination  is  not  obvious,  the  denominators  being  very  large,  divide  both 
denominators  by  the  remainder  [or  last  result]  of  the  reciprocal  division  of  the  two,  and  multiply 
by  the  two  quotients  the  reversed   denominators   together  with   their  quotients.     Other  methods 
may  be  similarly  devised  by  one's  own  ingenuity. 

Subtraction  also  takes  place  between  like  quantities  :  and  the  rule  must  be  therefore  applied  to 
difference.  Cii. 

*  The  author  now  teaches  the  method  of  finding  the  result  of  the  second  assimilation  consisting 
in  multiplication. 

First  multiply  separately  numerators  by  numerators,  and  denominators  by  denominators.  Then 
proceed  with  the  former  part  of  the  rule. 

•  ririwa,  flank  or  side. 
00 


Hi  BRAHMEGUPTA.  Chapter  XII. 

9,  In  the  third,  the  upper  numerator  is  multiplied  by  the  denominator.' 
In  the  two  next,  severally,  the  denominators  are  multiplied  by  the  denomi- 
nators ;  jjnd  the  upper  numerators  by  the  same  increased  or  diminished  by 
their  own  numerators.* 

Example  :  Half  a  quarter,  a  sixtli  part  of  a  quarter,  a  twelfth  part  of  a  quarter,  an  eighth  part 
of  ten  quarters,  a  fifth  part  of  seven  quarters :  summing  these  and  adding  three  twentieths,  let  us 
quickly  declare  the  amount.     It  is  a  sura,  which  we  must  constantly  pay  to  a  learned  astronomer. 

Statement:     H      H      i^       i£  ^      H      ^: 

O""'      i         A         A  U         -h       -in-     Answer:   the  sum  is  one. 

•  The  author  next  shows  the  method  of  finding  the  result  of  the  third  assimilation  consisting  in 
division. 

The  dividend  is  intended  by  the  term  upper  numerator :  and  the  middle  quantity  together  with 
it(  denominator  is  the  divisor.  Then  the  rule  for  transposition  of  numerator  and  denominator  (§  4) 
takes  effect. 

Example :  In  what  time  will  [four]  fountains,  being  let  loose  together,  fill  a  cistern,  which  they 
would  severally  fill  in  a  day;  in  half  a  one;  in  a  quarter;  and  in  a  fifth  part?* 

Statement:     1111         The  rule  being  observed;  i     t     J     4.    The  sum  is  12. 
1         i        i         i 
So  many  are  the  measures  in  a  day  with  all  the  fountains.     Then  by  the  rule  of  three,  if  so  many 
fillings  take  place  in  one  day,  in  what  time  will  one?    Statement:  *f  1 -J- | -J.    Answer:-^.     In  this 
portion  of  a  day,  all  the  fountains,  loose  together,  fill  the  cistern. 

Example :  One  bestows  an  unit  on  holy  men,  in  the  third  part  of  a  day ;  another  gives  the  same 
alms  in  half  a  day ;  and  a  third  distributes  three  in  five  days.  In  what  time,  persevering  in  those 
rates,  will  they  have  given  a  hundred  ? 

Statement:    113      And,  the  rule  being  observed,  ^    f    f.    Reducing  these  to  a  com- 

4     i     i 

mon  denominator,  and  summing  them,  the  result  is  ^;  the  total  amount,  which  all  bestow  in  alms 
in  a  day.  Then  by  the  rule  of  three,  if  so  many  fifths  of  an  unit  be  given  in  one  day,  in  how 
many  will  a  hundred  units  be  given  ? 

Statement:  '^  |  i  |  i^.     Answer:  17  4.  Cii. 

*  The  author  adds  this  rule  to  exhibit  reduction  of  fractional  increase  and  decrease  (hhagdnu- 
band'ha  and  bhdgapavdha-jdtij  ;  the  two  assimilations  Qa''-^  which  follow  next  after  the  first,  se- 
cond and  third;  that  is,  the  fourth  and  fifth. 

■  In  fractional  increase  the  numerators  standing  above  are  multiplied  by  the  denominators  aug- 
mented by  their  own  numerators ;  in  fractional  decrease  by  the  same  diminished  by  their  own 
numerators.     The  remainder  of  the  process  consists  in  reduction  to  homogeneous  form  as  before. 

Example  of  fractional  increase:  A  little  boy,  receiving  from  a  merchant  a  quarter  of  an  unit, 
dealt  with  commodities  for  gain,  during  six  days,  and  obtained  for  his  goods,  on  the  respective  days, 
u  price  with  both  profit  and  principal  equal  to  the  original  money  added  to  its  half,  its  third,  its 
quarter,  its  fifth  part,  its  sixth,  and  its  seventh:  what  was  the  amount?    Another  did  the  same  with 

•  LOdvatl,  §  94—95. 


Section  I.  RULE    OF    PROPORTION.  283 

10.  In  the  rule  of  three,  argument,  fruit  and  requisition  [are  names  of 
the  terms] :  the  first  and  last  terms  must  be  similar.^  Requisition,  multipHed 
by  the  fruit,  and  divided  by  the  argument,  is  the  produce." 

an  unit:  and  a  third  did  so,  with  six.     Tell  the  amount  of  their  dealings  also,  if  thou  be  conversant 
with  fractional  increase. 


Statement : 

i 

f 

h 

h 

h 

i 

i 

i 

i 

i 

i 

i 

i 

i 

i 

i 

i 

\ 

\ 

i 

!• 


The  denominator  four,  multiplied  by  the  denominator  two,  makes  8.  The  upper  numerator  1, 
multiplied  by  the  denominator  2  added  to  its  own  numerator  1,  viz.  3,  gives  3;  and  the  result  is  |. 
Proceeding  in  like  manner  with  three  and  the  rest  of  the  denominators,  the  amount  for  the  first  boy 
is  1 ;  for  the  second,  4;  for  the  third,  S-l. 

Example  of  fractional  decrease :  Eight  palas  of  white  sandal  wood  were  carried  by  a  merchant 
from  Canyacvbja  to  the  northern  mountain ;  and  at  five  places  offerings  were  made  by  him  of  a 
moiety,  a  third  part,  a  fifth,  a  ninth,  and  an  eighth  part  of  his  stock.     What  was  the  residue  ?• 

Statement:     8  Multiply  denominators  by  denominators  ;  and  the 

^  upper  numerators  by  denominators  lessened  by 

•§■  their  own  numerators.    This  being  done,  the 

f  answer  is  1  -^  [should  be  ^3^]. 

The  author  has  delivered  but  five  rules  of  reduction  or  assimilation  (jAti)  ;  and  has  omitted  the 
sixth,  as  it  consists  of  the  rest  and  is  therefore  virtually  taught.  It  has  been  given  by  Scanda- 
se'na  and  others  under  the  name  of  Bhuga-m&td.  Ch. 

See  Bhaga-mdtri-jati  in  Srid'hara's  abridgment :  §  56 — 57- 

'  The  middle  term  is  dissimilar.  Ch. 

*  TTie  rule  concerns  integers.  If  there  be  fractions  among  the  terms,  reduce  all  to  the  same 
denominator.  Ch. 

Example  :  A  person  gives  away  a  hundred  and  eight  cows  in  three  days ;  how  many  kine  does 
he  bestow  in  a  year  and  a  month  ? 

Statement:    Days  3.     Cows  108.     Days  390. 

Answer:     14040. 

Example :  A  white  ant  advances  eight  barley  corns  less  one  fifth  part  of  that  amount  in  a  day ; 
and  returns  the  twentieth  part  of  a  finger  in  three  days.  In  what  space  of  time  will  one,  whose 
progress  is  governed  by  these  rates  of  advancing  and  receding,  proceed  one  hundred  yojanas  ? 

Statement :    Daily  advance  8  less  ^.    Triduan  retrogradation  -^^  fiiig.     Distance  100  y. 

•  The  text  of  tliis  example,  its  statement  and  the  answer  are  very  corrupt. 

o  o  2 


3B4  BRAHMEGUPTA.  Chapter  XII. 

II.  In  the  inverse  rule  of  three  terms,  the  product  of  argument  and  fruit, 
being  divided  by  the  demand,  is  the  answer.' 

II  — 12.  In  tlie  case  of  three  or  more*  uneven  terms,  up  to  eleven,'  transi- 
tion of  the  fruit  takes  place  on  both  sides. 

The  product  of  the  numerous  terms  on  one  side,  divided  by  that  of  the 
fewer  on  the  other,  must  be  taken  as  the  answer.  In  all  the  fractions,  transi- 
tion of  the  denominators,  in  like  manner,  takes  place  on  both  sides.* 

Here  this  maxim  applies  "  eight  breadths  of  a  barley  corn  are  one  finger ;  twenty-four  fingers, 
one  cubit;  four  cubits,  one  staff;  eight  thousand  staves,  one  yojana." 

The  daily  advance,  in  a  homogeneous  form,  is  ^  of  a  barley-corn.  Retrogradation  in  three 
days,  -j^  of  a  finger;  in  one  day,  by  tlie  proportion,  '  as  three  to  that,  so  is  one  to  how  much?'  ■^. 
The  daily  advance,  divided  by  eight,  is  reduced  to  fingers,  viz.  f  J  or  f .  Reduced  to  the  same  de- 
nominator as  the  retrogradation,  |J.  Subtracting  the  retrogradation,  the  neat  progress  is  J  J.  A 
hundred  yojanas,  turned  into  sixtieths  of  fingers,  are  46O8OOOOOO.  Then  |J  |  •}•  |  .«6»aoooooo  | 
Answer:  Days  98042553.  Ch. 

*  Example :  The  load  (bhira)  was  before  weighed  with  a  tuUi  o( six  tuvernas,  tell  me,  promptly, 
how  much  will  it  be,  if  weighed  out  with  one  of  five  i 

Statement:     su.6}    bhd  I ;   lu  5. 

Answer :    24  hundred  palas. 

Here  this  maxim  serves  "  sixteen  grains  of  barley  are  one  mdsha;  sixteen  of  these,  a  mverna; 
four  of  which,  make  one  pala;  and  two  thousand  palas,  a  bhdra." 

Example  :  Tell  me,  quickly,  how  many  ten  c'hdrU,  which  were  meted  with  a  measure  of  three 
and  a  half  to  the  jirasfha,  will  be  when  meted  with  one  of  five  and  a  half? 

Statement:     ca  ^  ;  c'h&iO;   cu^. 

Answer:    c'hdS,  md  1,  drol,  d3,  pral,  cu-^. 

Maxim  applicable  to  the  instance.  "  Four  cu'dabas  make  one  prast'ha;  four  of  these,  one  ffd'haca; 
four  (i'd'Aacas,  a  hollow  purdlana;*  four  of  these,  a  m<{nic({;  four  mdnicds,  one  c'hdri,  a  measure 
familiar  to  the  people  of  Magad'/ia."  Ch. 

The  case  of  three  terms  must  be  excluded,  being  already  provided  for  (§  10);  and  the  rule 
concerns  five,  seven,  nine  and  eleven  terms.  Cii. 

*  Uneven  ;  not  even,  as  four,  &c.  would  be.  Cn. 

*  Example:   The  interest  is  settled  at  ten  in  the  hundred  for  three  months:  let  the  interest  of 

sixty  lent  for  five  months  be  told. 

Statement:       3  5  Answer:   10. 

100         60 
10 

Transferring  the  term  ten  to  the  second  side,  the  product  of  this  becomes  the  more  numerous 
one,  viz.  3000 ;  which,  divided  by  the  product  of  the  fewer,  three  and  a  hundred,  viz.  300,  gives 
10  ;  the  interest  for  five  months. 

Example:  If  the  interest  of  thirty  and  a  half,  for  a  month  and  one  third,  be  one  and  a  half:  be 
it  here  told  what  is  the  interest  of  sixty  and  a  half  for  a  year? 

*  Chita  piiritana.     It  U  tliedriin'a  ofSniVBABA  and  BiiVscAnA.    See  Lit.  $ B,  and  Can.  itfr.  $ 5. 


Section  I.  BARTER.  fi85 

1 3.     In   the  barter  of  commodities,   transposition  of  prices  being  first 

Statement  of  homogeneous  terms:   ^         ^ 

f 

Transposition  of  the  fruit  and  of  the  denominators  having  been  made,  the  statement  is  4         12 

1  3 
6l       121 

2  2 
2  3 

Whence  the  answer  is  found  as  before  26-^. 

Example:    Forty  is  the  interest  of  a  hundred  for  ten  months.     A  hundred  has  been  gained  in 

eight  months.     Of  what  sum  is  it  the  interest? 

Statement:    10  8 

100 
40       100 

Mutually  transferring  the  fruits,  forty  on  one  side  and  a  hundred  on  the  other,  the  statement 

is    10  8         Whence  proceeding  as  above,  the  answer  comes  out  t^, 

100  * 

100         40 

The  same  answer  may  be  found  by  two  proportions  or  sets  of  three  terras. 
Example  of  seven  terms:   If  three  cloths,  five  [cubits]  long  and  two  wide,  cost  six  paiias,  and  ten 
have  been  purchased  three  wide  and  six  long,  tell  the  price. 

Statement :    2  3        Transposing,  and  proceeding  as  in  the  rule  of  five,  the  answer  is  36.' 

5  6 
3  10 
6 

Example  :    If  three  cloths,  two  wide  and  five  long,  cost  six  panas;  tell  me  how  many  cloths, 

three  wide  and  six  long,  should  be  had  for  six  times  six  i 

Statement:    2        3        Making  a  mutual  transfer,  and  in  other  respects  preceding  as  above, 

^         "  the  answer  is  10. 

3 

6  36 

The  answer  may  be  proved  by  three  proportions  or  sets  of  three  terms. 

Example  of  nine  terms:    The  price  of  a  hundred  bricks,  of  which  the  length,  thickness  and 
breadth,  respectively,  are  sixteen,  eight  and  ten,  is  settled  at  six  dindras:  we  have  received  a  hun- 
dred thousand  of  other  bricks  a  quarter  less  in  every  dimension :  say  what  we  ought  to  pay. 
Statement:    l6  12        Transposition  of  fruit  and  of  denominator  being  made,  the  answer 

*  j^  comes  out  2531  J. 

100     100000 

The  answer  may  be  proved  by  four  proportions  or  sets  of  three  terms. 

Example  of  eleven  terms:  Two  elephants,  which  are  ten  in  length,  nine  in  breadth,  thirty-six  in 
girt,  and  seven  in  height,  consume  one  drona  of  grain.  How  much  will  be  the  rations  often  other 
elephants,  which  area  quarter  more  in  height  and  other  dimensions? 


S86  BRAHMEGUPTA.  Chapter  XII. 

terms  takes  place ;  and  the  rest  of  the  process  is  the  same  as  above  direct- 
ed.' 

Operations,*  subservient  to  the  eight  investigations,'  have  been  thus  ex- 
plained. 

Statement:     2     10    The  fruit  and  denominators  being  transposed,  and  proceeding  as  above,  the 
10     ^         SLiawer  comei  out  12  droiias,  3  prast' has,  1^  cuJaba. 

9     V 
36    45 

7     V 
1 


'  Example:  If  a  hundred  of  mangoes  be  purchased  for  ten  paiias;  and  of  pomegranates  for 
eight ;  how  many  pomegranates  [should  be  exchanged]  for  twenty  mangoes  ? 

Statement:       10         81  f      8       10 

100     100  >and  after  transposition  of  prices  and  transition  of  fruit  ;<  100     100 

20  3  (.20 

Answer:     25  pomegranates. 

*  Paricarman  :  algorithm,  or  logistics.     See§l. 

These  operations,  us  affecting  surd  roots,  unknown  quantities,  affirmative  and  negative  terms, 
and  cipher,  the  author  will  teach  in  the  chapter  on  (cuiiaca)  the  pulverizer ;  and  we  shall  there 
explain  them  under  the  relative  rules.  Ch. 

*  Vyttv»h&ra,  ascertainment,  or  determination.    §  1 . 


(     287     ) 


SECTION   II. 


• 


MIXTURE. 

14.  The  argument  taken  into  its  time  and  divided  by  the  fruit,  being- 
multiplied  by  the  factor  less  one,  is  the  time.*  The  sum  of  principal  and 
interest,  being  divided  by  unity  added  to  its  fruit,  is  the  principal.* 

15.  The  product  of  the  time  and  principal,  divided  by  the  further  time, 
is  twice  set  down.^     From  the  product  of  the  one  by  the  mixt  amount, 

'  The  principal  sum,  multiplied  by  the  time,  reckoned  in  months,  which  regulates  the  interest, 
is  divided  by  the  interest :  and  the  quotient  is  multiplied  by  one  less  than  the  factor ;  (if  the  double 
be  inquired,  by  one;  if  the  triple,  by  two;  if  the  sesquialteral,  by  half;)  the  result  i»  the  number 
of  months,  in  which  the  sum  lent  is  raised  to  that  multiple.  Ch. 

Example  :  If  the  interest  of  two  hundred  for  a  month  be  six  drammas,  in  what  time  will  the 
same  sum  lent  be  tripled  ? 

Answer  :     66  f  months. 

Example  :  If  the  interest  of  twenty  paiias  for  t%vo  months  be  five,  say  in  what  time  will  ray 
principal  be  raised  to  the  sesquialterate  amount  ? 

Answer  :     4  months.  lb. 

■^  Subtracting  this  from  the  amount  given,  the  remainder  is  the  interest.  Or  multiply  the 
amount  of  principal  and  interest  by  the  interest  of  unity  and  divide  by  unity  added  to  its  interest, 
the  quotient  is  the  interest.  Ch. 

Example :  A  sum  lent  at  five  in  the  hundred  by  the  month  amounted  to  six  times  six  in  ten 
months  ;  what  was  the  sum  in  this  case  lent  ? 

Answer:     Principal  24.     Interest  12. 

Example :  Eight  hundred  suverrias  were  delivered  to  a  goldsmith  with  these  directions  :  "  make 
vessels  for  the  priests,  and  take  five  in  the  hundred  for  the  making."  He  did  as  directed.  Tell 
me  the  amount  of  wrought  gold. 

Answer :     Wrought  gold  76 1  ^.     Fashion  38  ^. 

The  rule  is  applicable  to  analogous  instances.  lb. 

*  The  rate  of  interest  by  the  hundred,  at  which  the  money  was  lent  by  the  creditor,  is  not 
known.    All  that  is  known  is,  that  the  interest  for  a  given  number  of  months  has  been  received 


^8  BRAHMEGUPTA.  Chapter  XII. 

added  to  the  square  of  half  the  other,  extract  the  square-root :  tliat  root, 
less  half  the  second,  is  the  interest  of  principal.' 

16.  The  contributions,  taken  into  the  profit  divided  by  the  sum  of  the 
contributions,  are  the  several  gains  :*  or,  if  there  be  subtractive  or  additive 
differences,  into  the  profit  increased  or  diminished  by  the  differences ;  and 
the  product  has  the  corresponding  difference  subtracted  or  added.' 

and  lent  out  again  at  the  same  rate,  and  has  amounted  in  a  given  number  of  months  to  a  certain 
sum,  principal  and  interest.  The  rate  of  interest  is  required  ;  and  the  rule  is  propounded  to  find 
it.  Ch. 

'  Example  :  Five  hundred  drammas  were  a  loan  at  a  rate  .of  interest  not  known.  The  interest 
of  that  money  for  four  months  was  lent  to  another  person  at  the  same  rate  ;  and  it  accumulated  in 
ten  months  to  seventy-eight.    Tell  the  rate  of  interest  on  the  principal. 

Answer :     60. 

Here  the  demonstration  is  to  be  shown  algebraically  by  solution  of  a  quadratic  equation,  as 
follows.  If  the  interest  of  five  hundred  for  four -months  be  y^iaca;  what  is  the  interest  of  ^/iraca 
for  ten  months.  Here,  transition  of  the  fruit  taking  place  (§  12),  the  principal  taken  into  the 
time  is  the  product  of  the  fewer  terms ;  and  the  product  of  the  numerous  terms  is  the  square  of 
y&vaca  multiplied  by  tht  further  time.  Those  products  are  reduced  to  least  terras  by  a  common 
divisor  equal  to  the  further  time :  as  is  directed  (§  15).  Thus,  by  the  rule  of  three  terms,  the 
answer  comes  our  yav  -j^;  the  interest  of  ydvaca.  Adding  yixaca,  it  is  the  mixed  amount;  that 
is,  yav-^^  y'^\-  This  is  equal  to  seventy-eight.  Reducing  to  uniformity  and  dropping  the 
common  denominator,  the  two  sides  of  the  equation  become  :  1st  side  ya  1 1  ya  200  ru  0 ;  2d 
side  yavO  yaO  ruloGO.  By  the  rule  in  the  chapter  on  cuiiaca,  "of  the  coefficient  of  the 
tquare,  &c."*  the  value  oi y&vaca  comes  out  60;  which  is  equal  to  that  above  found.  Cn. 

*  Pracshepaca :  what  is  thrown  or  cast  together :  the  proposed  quantities,  of  which  an  union  is 
made.  Ch. 

LabcThi,  profit.     L/ibha,  gain.     Uttara,  difference. 

*  Example  of  the  first  rule  :  A  horse  was  purchased,  with  the  principal  sums,  one,  &c.  up  to 
nine,  by  dealers  in  partnership;  and  was  sold  [by  them]  for  five  less  than  five  hundred.  Tell  me 
what  was  each  man's  share' of  the  mixt  amount. 

Statement:  Contributions  1,  2,  3,  4,  3,  6,  7,  8,  <).  Their  sum  45.  The  profit  495,  di- 
vided by  that,  gives  the  quotient  11  ;  by  which  the  contributions  being  multiplied,  become  11,  22, 
33,  44,  55,  66,  77,  88,  S9-     Tiiese  are  the  several  gains  of  the  dealers. 

Example  of  the  second  rule  :  Four  colleges,  containing  an  equal  number  of  pupils,  were  invited 
to  partake  of  a  sacrificial  feast.  A  fifth,  a  half,  a  third,  and  a  quarter  came  from  the  respective 
colleges  to  the  feast ;  and,  added  to  one,  two,  three  and  four,  they  were  found  to  amount  to  eighty- 
seven  ;  or,  with  those  differences  deducted,  they  were  sixty-seven. 

•  Varg'-ihttitt-rifdnim,  &c.    See  Algebra  of  BraAm.  $  S4. 


Section  II.  MIXTURE.  289 

Statement :     1     2     3     4     Reduced  to  a  common  denomination  and  the  denominator  being 

i     i    i    i 
dropped,  they  are     12       3       4      The  number  given  is  87.     It  is  the  profit  (5  1 6).     Deduct- 

12  30  20  15 
ing  the  sum  of  the  differences  (1,  2,  3,  4)  viz.  10,  the  remainder  is  77  :  vvhich,  divided  by  the 
sum  of  the  contributions,  77,  gives  1  ;  and  the  contributions,  multiplied  by  this  quotient,  and 
having  their  differences  added,  become  13,  32,  23,  ip;  or,  added  together,  87.  The  number  of 
disciples  in  each  college  is  60.  Or,  subtracting  the  differences,  the  number  of  pupils  that  came 
from  the  four  colleges  to  the  feast  is  1 1,  28,  17,  U ;  total  67. 

Example  :  Three  jars  of  liquid  butter,  water,  and  honey,  contained  thirty-two,  sixty,  and 
twenty-four  palas  respectively :  the  whole  was  mixed  together,  and  the  jars  again  filled  ;  but  I 
know  not  the  several  numbers.  Tell  me  the  quantity  of  butter,  of  water  and  of  honey,  in  each  jar- 
Statement:  Butter  32;  water  60;  honey  24:  these  are  the  contributions  (§  l6).  Their  sum, 
ll6;  by  which  divide  the  profit,  viz.  butter  32,  the  quotient  is  -^.  The  contributions,  severally 
multiplied  by  this,  give  the  gains,  viz.  butter  in  the  butter-jar  8 1^ ;  in  the  water-ji'.r,  l6  ^ ;  in 
the  honey-jar,  6"^.  So  water  in  the  water-jar  3 1  jig ;  in  the  honey-jar,  12^;  in  the  butter- 
jar,  l6^:  honey  in  the  hoiiey-jar  4 If  ;  in  the  butter-jar,  6|^;  in  the  water-jar,  12^.     Ch. 

Remark. — In  this  chapter  of  arithmetic,  the  computation  of  gold  [or  alligation]  is  omitted.     On 

that  account,  the  following  stanza  is  here  subjoined.     "  Add  together  the  products  of  the  weight 

into  the  fineness  of  the  gold  ;    and   divide   by  the  given  touch  :  the  quotient  is  the  quantity.     Or 

divide  by  the  sum  of  the  gold,  the  quotient  is  the  touch." 

Thus  five  suvernas  of  the  touch  of  twelve,  six  of  that  of  thirteen,  and  seven  of  that  of  fourteen, 

(5       6       7     or,  multiplying  weight  into  fineness,  60,  78,  98  ;)  being  added  together,   are  236. 
12     13     14 

By  whatever  touch  this  mass  is  divided,  the  quotient  is  the  quantity  of  gold  of  that  fineness.     For 

instance,  if  the  touch  be  sixteen,  dividing  by  l6,  the   quotient  is  14  su.    12  m&.     Dividing  by 

fifteen,  it  is  l6 -^.*    The  number  of  suvernat  in  the  mass  is  of  one  fineness.     The  mass  of  gold, 

therefore,  is  to  be  divided  by  the  sum  of  the  weights:  the  quotient  is  the  touch  of  that  number  of 

tucernat.    Thus,  dividing  the  aggregate  of  products  of  weight  into  fineness,  236,  by  the  sum  of 

the  weight!  18,  the  quotient  13  -}  is  the  touch.  Ch. 

*  So  tbe  MS.     But  )hogld  be  15  f }. 


P  T 


^}«(J  (    290    ) 


SECTION  III, 


PROGRESSION. 

17.  The  period  less  one,  multiplied  by  the  common  difference,  being 
added  to  the  first  term,  is  the  amount  of  the  last.  Half  the  sum  of  last  and 
first  terms  is  the  mean  amount:  which,  multiplied  by  the  period,  is  the  sum 
of  the  whole.* 

•  To  find  the  contents  of  a  pile  in  the  form  of  half  the  meru-yantra  [or  spindle].  Ch. 

Example  :  A  stack  of  bricks  is  seen,  containing  five  layers,  having  two  bricks  at  the  top,  and 
increasing  by  three  in  each  layer :  tell  the  whole  number  of  bricks. 

Statement:     Init.  2  ;  DiflF.  3  ;  Per.  5.     Answer:  40. 

Example :  The  king  bestowed  gold  continually  on  venerable  priests,  during  three  days  and  a 
ninth  part,  giving  one  and  a  half  \bharas\  with  a  daily  increase  of  a  quarter  :  what  were  the  mean 
and  last  terms,  and  the  total  ? 

Statement:     Init.  1 J  ;  DiflF.  J  ;  Per.  3^. 

Period  ^,  less  one,  is  ^ ;  multiplied  by  the  difference,  it  is  ^ ;  and  added  to  the  first  terra, 
becomes^.  This  is  the  last  term.  Added  to  the  first  term  and  halved,  it  gives  ii^.  This  is 
the  mean  amount:  multiplied  by  the  period,  it  yields  the  total -ff^;  or  5  bhdras,  9  hun'^i'C*! 
[;)a/ai]  and -g^  [of  a  hundred]. 

Example  :  Tell  the  price  of  the  seventh  conch  ;  the  first  being  worth  six  parias,  and  the  rest 
increasing  by  a  pana  ? 

Statement:     Init.  6  ;  Diff.  1  ;  Per.  7.     Answer:  12. 

Example:  A  man  gave  his  son-in-law  sixteen  pa«(W  the  first  day;  and  diminished  the  present 
by  two  a  day.  If  thou  be  conversant  with  progression,  say  how  many  had  he  bestowed  when  the 
ninth  day  was  past  ? 

Statement:  Init.  16;  Diff.  2;  Per.  9-  Answer:  72  ;  received  by  the  son-in-law  :  or  72  the 
father-in-law's;  being  his  disbursement. 

Example  :  [The  first  term  being  five  ;  the  difference  three  ;  and  the  period  eight ;  what  is  the 
sum  ?  the  last  term  ?  and  the  mean  amount  ?*] 

Statement:     Init. .S;  Diff.  3;  Per.  8.     Answer:  Last  term  26.     Mean  Y-     Sura  124. 

Here  one  side  is  to  be  put  equal  to  the  period  of  the  progression  ;  and  a  second,  equal  to  its 

*  The  terms  of  the  question  are  wanting  in  the  original. 


Section  III.  PROGRESSION.  291 

18.  Add  the  square  of  the  difFerence  between  twice  the  initial  term  and 
the  common  increase,  to  tlie  product  of  the  sum  of  the  progression  by  eight 
times  the  increase  :  the  square-root,  less  the  foregoing  remainder  divided  by 
twice  the  common  increase,  is  the  period.' 

mean  term  :  and  the  figure  of  a  rectangle  is  to  be  thus  exhibited.  Then  30  many  little  areas,  in 
the  figure  of  the  progression,  [formed]  by  its  area,  as  are  excluded  [on  the  one  part,]  are  gathered 
in  front  within  that  oblong.     Therefore  the  finding  of  the  area  is  congruous.  Ch. 

To  show  the  rule  for  finding  the  sum  of  a  series  increasing  twofold,  or  threefold,  &c.  three 
stanzas  of  my  own  [the  commeutator  Prit'hu'daca's]  are  here  inserted  :  '  At  half  the  given  pe- 
riod put  "square;"  and  at  unity  [subtracted]  put  "  multiplier;"  and  so  on,  until  the  period  be 
exhausted.  Then  square  and  multiply  the  common  multiplier  inversely  in  the  order  of  the  notes. 
Let  the  product  less  one  be  divided  by  the  multiplier  less  one,  and  multiplied  by  the  amount  of 
the  initial  term ;  and  call  the  result  area  [or  sum],  the  progression  being  [geometrical]  twofold,  &c. 
This  method  is  here  shown  from  the  combination  of  metre  in  prosody.'  The  meaning  is  this  :  if 
the  period  be  an  even  number,  halve  it,  and  note  "square"  in  another  place;  when  the  number 
is  uneven,  subtract  unity,  and  note  "  multiplier"  in  that  other  place  and  contiguous.  Proceed  in 
the  same  manner,  halving  when  the  number  is  even,  and  subtracting  one  when  it  is  uneven,  and 
noting  the  marks  "  square"  and  "  multiplier,"  one  under  the  other,  in  order  as  they  are  found 
until  the  period  be  exhausted.  The  lowermost  mark  must  of  course  be  "  multiplier."  It  is  equal 
to  the  [common]  multiplier  [of  the  progression].  Setting  down  that  on  the  working  ground, 
square  the  quantity  when  "  square"  is  noted,  and  multiply  it  where  "  multiplier"  is  marked  :  pro- 
ceeding thus  in  the  inverse  order,  to  the  uppermost  note.  From  the  quantity  which  is  thus  ob- 
tained, subtract  unity;  divide  the  remainder  by  the  amount  of  the  [common]  multiplier  less  one; 
and  multiply  the  quotient  by  the  number  of  the  initial  term.  This  being  done,  the  product  is  the 
sum  of  a  progression,  where  the  difference  is  twofold  or  the  like.  7J. 

Example  :     How  mucH  is  given  in  ten  days,  by  one  who  bestows  six  with  a  threefold  increase 
daily  ? 

Statement:     Init.  6;  Com.  mult.  3;  Per.  10.     Answer:  l??!**. 

Example :  Say  how  much  is  given  by  one,  who  bestows  for  three  days,  three  and  a  half  [daily] 
with  increase  measured  by  the  [common]  multiplier  five  moieties? 

Statement :     Init.  |  ;  Diff.  mult.  | ;  Per.  3. 

Put"  mult."  for  subtraction  of  unity;  "  square"  for  the  half;  and  again  "mult."  for  unity 

subtracted :  mult.      The  multiplier  is  two  and  a  half  or  ^,  at  the  first  place.     Squared  at  the 
sq. 
mult, 
second,  it  is  «^  ;  and  again  multiplied  at  the  third,  if*.     Unity  being  subtracted,  it  is  >^'.     Di- 
vided by  multiplier  less  one  (-J)  it  becomes  ^.     This  multiplied  by  the  initial  term,  and  abridged, 
yields  2|3. 

'  The  first  term,  common  increase,  and  total  amount,  being  known,  to  find  the  period.     Ch. 

Example:  Say  how  many  are  the  layers  in  a  stack  containing  a  hundred  bricks,  and  having 
at  the  summit  ten,  and  increasing  by  five. 

Statement :     Init.  10;  Cora.  diff.  5 ;  Per.  ?     Sum  100.      ' 

pp2 


SOS  BRAHMEGUPTA.  Chapter  XII. 

19.     One,  &c.  increasing  by  one,  [being  added  together]  are  the  sum  of  a 

Operation:  Twice  the  initial,  20,  less  the  increase  5,  is  15;  the  square  of  which  is  2?5.  The 
sum  100,  eight  (8)  and  increase  5,  multiplied  together,  make  4000.  Add  to  this  the  square  uf 
the  remainder,  225,  the  total  is  4225.  Its  square-root  65,  less  the  foregoing  remainder  15,  gives 
50;  which  diWdfd  by  twice  the  common  increase,  10,  yields  the  period  5. 

So  in  other  c.ises  liiiewise. 

Here  the  principle  is  the  resolution  of  a  quadratic  equation.  For  instance:  Init.  10;  Com. 
diff.  5;  Per.  yal.  This  less  one  [§  17]  becomes  i/a  I  ru  I ;  which,  multiplied  by  the  common 
increase  5,  makes  ^a  5  r«5;  and  added  to  the  initial  term  10,  affords  ya  5  ru5,  the  last  terra. 
Added  to  first  term,  it  is  t/a  5  r«  15  ;  which  halved  gives  j/af  ru  ^.  It  is  the  mean  amount ;  and, 
multiplied  by  the  period,  yields  t/av  ^  J'"  V>  '''^  ''""'  °f  ^^^  whole  :  which  is  equal  to  a  hundred. 
Making  an  equation,  two  is  multiplier  of  a  hundred,  being  the  [denominator,  or]  divisor  standing 
beneath,*  as  before  shown.  The  quantity  being  so  treated,  and  the  rule  for  preparing  the  equa- 
tiont  observed,  the  first  side  of  the  equation  is  yav  5  yaiS;  and  the  second  side  is  ru  200. 
Then,  proceeding  by  the  rule  "  Multiply  by  four  times  [the  coefficient  of]  the  square"  and  so 
forth,!  'he  absolute  number  becomes  4000.  It  is  the  product  of  the  multiplication  of  the  sum, 
common  increase  and  eight.  For  the  multiplier  being  two,  the  quantity  must  be  multiplied  by 
that  and  by  four :  wherefore  multiplication  by  eight  is  specified.  The  unity,  which  is  subtracted 
from  y&vaca,  becomes  negative :  it  is  multiplied  by  the  common  increase  ;  and  thus  a  number 
equal  to  the  common  increase  becomes  negative :  this  being  added  to  the  initial  term,  and  the 
result  again  added  to  the  initial  term,  an  affirmative  quantity  equal  to  twice  the  initial  is  intro- 
daced  :  taken  together,  the  difference  is  the  sum  of  the  negative  and  affirmative  quantities  and  is 
fitly  called  the  remainder.  It  is  here  tiie  coefficient  of  y&vaca.  Then,  observing  the  rule  for 
adding  "  the  square  of  [the  eoetficient  of]  the  middle  term,"||  the  absolute  number  is  as  here  shown  : 
viz.  4225.  Its  root,  65,  less  the  [coefficient  of  the]  middle  term,  is  50  :  which,  divided  by  twice 
the  [coefficient  of  the]  square,  is  the  middle  [term  of  the  equation],  that  is  to  say  the  period  of 
the  progression:  viz.  5.     For  ydvaca  is  here  the  period. 

If  the  initial  term  be  unknown,  but  the  common  increase,  period  and  sum  be  given,  divide  the 
sum  of  the  progression  by  the  period  :  the  quotient  is  the  mean  amount.  Double  it;  and  subtract 
the  product  of  the  period  less  one  taken  into  the  common  increase:  half  the  remainder  is  the  initial 
term.  For  instance:  Init,?  Diff.  3  ;  Per.  5;  Sum  40.  This,  divided  by  the  period,  gives  8,  the 
mean  amount;  which  doubled  is  l6.  The  period  less  one  is  4;  and  the  common  increase  3:  their 
product  12.  Subtracting  this  from  the  foregoing,  the  remainder  is  4  :  its  half  2  is  the  initial  term. 
This  is  to  be  applied  in  olher  cases  also. 

Where  the  common  increase  is  unknown  ;  divide  in  like  manner  the  sum  by  the  period,  the  quo- 
tient is  the  mean  amount.     Double  it ;  and  subtract  twice  the  initial  term  :  the  quotient  of  the  re- 

•  Aghauehtt-cVhidn. 
t  Algebra  of  BiuAm.  §33. 

X  See  Algebra  of  Bfahm.  §  S3.    A  rule  of  (be  >aine  import  with  that  of  SaiD'aABi  cited  by  'BHttckn.A.      Vip- 
fan,  $  ISl. 
B  Ibid. 


Section  III.  PROGRESSION.  293 

given  period.  That  sum  being  multiplied  by  the  period  added  to  two,  and 
being  divided  by  three,  is  the  sum  of  the  sums.' 

20.  The  same,'  being  multiplied  by  twice  the  period  added  to  one,  and 
being  divided  by  three,  is  the  sum  of  the  squares.'     The  sum  of  the  cube? 

mainder  by  the  period  less  one,  is  the  common  increase.  For  instance;  Init.  2;  DifF. ?  Per.  7. 
Sum  TJ.  Deducing  the  mean  amount  from  the  sum  by  the  period,  doubling  it  [and  proceeding 
in  other  respects  as  directed,  the  common  difference  comes  out  3.*] 

[If  the  first  term  and  common  difference  be  both  unknown,  deduce  the  mean  amount  from  the 
sum  by  its  period  ;  and  doubling  it*]  set  down  the  result  as  a  reserved  quantity.  Then  put  an  ar- 
bitrary common  increase;  and  by  that  multiply  the  period  less  one.  Subtract  the  product  from 
the  reserved  quantity  :  the  moiety  of  the  residue  is  the  initial  term;  and  the  common  increase,  as 
assumed.  For  instance  :  Init.?  Diff. ?  Per.  9.  Sum  576.  The  quotient  of  this  by  the  period  is 
the  mean  amount  6-i  :  the  double  of  which  is  called  the  reserved  quantity,  129.  Putting  one  for 
the  common  increase,  the  period  less  one,  multiplied  by  that,  is  8  :  which  being  subtracted  from  the 
reserved  quantity,  and  the  remainder  being  halved,  yield  Initial  terra  60;  Dift'.  1  ;  Per.  9-  Or> 
putting  two  for  the  common  difference,  the  result  is  Init.  56;  Diff.  2 ;  Per.  9;  Sum  576.  Or, 
assuming  two  and  a  half,  it  comes  out  Init.  54  ;  Diff.  | ;  Per.  9;  Sum  576.  This  is  applicable  in 
all  cases  and  \x\  witole  numbers. 

But,  if  the  fii-st  term,  common  difference  and  period  be  all  three  unknown  ;  put  an  arbitrary 
number  for  the  period,  and  proceed  as  just  shown. 

If  the  difference,  period,  mean  amount  and  sum  total  of  a  progression  be  required  in  square  num- 
bers, put  any  square  {|uantity  for  the  period  of  the  progression.  The  period  multiplied  by  sixteen 
serves  for  the  common  difference;  and  the  square  of  two  less  than  the  period  for  the  initial  term. 
With  these,  the  mean  amount  and  sum  total  are  found  as  before.  For  instance:  let  the  square 
number  9  be  the  period.  Multiplied  by  sixteen,  it  gives  141.  The  period  less  two  is  7  ;  the 
square  of  which,  49,  is  the  initial  term.  Init.  49;  Diff.  144;  Per.  9;  Mean  amount  625.  Sum 
5625.     All  five  are  square  numbers. 

In  like  manner  a  variety  of  examples  may  be  devised  for  the  illustration  of  the  subject.  For 
fear  of  rendering  the  book  voluminous,  they  are  not  here  instanced  :  as  we  have  undertaken  to  in- 
terpret the  whole  astronomical  system  (sidd'Mnta).  Cii. 

'   A  rule  to  find  the  content  of  a  pile  of  sums.  Ch. 

Exampleif  Per.  5.  The  sum  of  this,  consisting  of  the  arithmeticals  one,  &c.  increasing  by 
one,  is  15,  which,  multiplied  by  the  period  added  to  two,  viz.  7,  is  105.  Divided  by  three,  the 
quotient  is  35,  the  content,  in  bricks,  of  a  pile  of  sums,  the  period  of  which  is  five.  Cii. 

*  To  find  the  content  of  a  pile  of  quadrates  ;  and  one  of  cubics.  Ch. 

*  Example  if  Per.  5.  This  doubled,  and  having  one  added  to  it,  is  1 1.  The  sum  of  the  pe- 
riod, viz.  15,  being  multiplied  by  that,  is  l65  :  which  divided  by  three,  gives  55.  It  is  the  content, 
iii  bricks,  of  a  pile  of  quadrates,  the  period  of  which  is  five.  Ch. 

*  Tlie  manuscript  i<  here  de6cient :  but  tlie  context  renders  it  easy  to  supply  tlie  defect. 

t  The  questioiu  are  not  proposed  in  words  at  length :  or  else  the  manuscript  \t  in  iliis  respect  deficient. 


294  BRAHMEGUPTA.  Chapter  XII. 

is  the  square  of  the  same.*     Piles  [may  be  exhibited*]  with  equal  balls  [or 
cubes  ;*  as  a  practical  illustration*]  of  these  [methods.*] ' 

^'•'"Example:!     Per.  5.    The  sum  of  this  is  15.     Its  square  is  225 ;  the  content,  in  bricks,  of  a 
pile  of  cubics,  the  period  of  which  is  five. 

*  Bricks  in  the  form  of  regular  dodecagons. — Ch.     Meaning  cubes.     See  LMvati,  §  7,  note. 

*  As  the  author  has  mentioned  a  pile  of  balls,  the  method  of  finding  the  content  is  here  shown. 
Let  the  area  of  the  circle  be  found  by  the  method  subsequently  taught  [§40]  and  be  reserved. 
The  square-root  of  it  is  to  be  extracted ;  and  by  that  root  multiply  the  reserved  area.  This  being 
done,  the  area  of  the  globe  is  found.  But  in  the  circle  the  area  is  an  irrational  quantity.  This 
again  then  is  to  be  multiplied  by  the  square  of  the  surd  :  and  the  square-root  of  the  product  is  the 
content  of  the  globe  and  is  a  surd.  Cu. 

*  Chaturveda, 

t  The  quettions  are  not  propMed  in  words  at  length  ■.  or  elie  the  manutoript  » in  tbii  ropect  deficient. 


I 


(     295     ) 


SECTION  IV. 


PLANE    FIGURE.' 

TRIANGLE  and  QUADRILATERAL. 

21.  The  product  of  half  the  sides  and  countersides''  is  the  gross  area  of  a 
triangle  and  tetragon.'     Half  the  sum  of  the  sides  set  down  four  times,  and 

•  Triangles  are  three ;  tetragons  five  ,  and  the  circle  is  the  ninth  plane  figure.  Thus  triangles 
are  (tama-tribhuja)  equilateral,  (dwi-sama-tribhuja)  isosceles,  and  (vishamn-tribhiija)  scalene. 
Tetragons  are  (sama-chaturasra)  equilateral ;  (dt/ata-sama-chaturasra)  oblong  with  equal  sides  [two 
and  two];  ( dwi-sama-cltaturasra)  having  two  equal  sides;  ('/«-Mn!a-cAa/«rasraJ  having  three  sides 
equal;  (vishama-chalurasra)  \\a.\\ng  a.\\  unequal.  Ch. 

*  Bdhu-pratibdhu,  or  bhuja-pratibhuja  (§23) :  opposite  sides. 

'  Example :     What  is  the  area  of  an  equilateral  triangle,  the  side  of  which  is  twelve  ? 

Statement-     12/  \12     The  sum  of  sides  and  of  countersides,  13  and  24;  their  moieties  6  and 
L^ A  12  ;  the  product  of  which  is  72,  the  gross  area.  . 

Example :  What  is  the  area  of  an  isosceles  triangle  the  base  of  which  is  ten  and  the  sides 
thirteen  ? 

Statement:     13/  \l3     The  moieties  of  the  sums  of  opposite  sides,  5  and  i3;  their  product  65, 

L \  the  gross  area. 

10 

Example :     What  is  the  area  of  a  scalene  triangle,  the  base  of  which  is  fourteen  and  the  sides 

thirteen  and  fifteen  ? 

Statement:     W   \l5      Answer:     98  the  gross  area. 


14 
Example  :     What  is  the  area  of  an  equilateral  tetragon,  the  side  of  which  is  ten  \ 
10 


Statement:     10 


10       Answer :     100,  the  gross  as  well  as  exact  area. 


10 


296  BRAHMEGUPTA.  Chapter  XII. 

severally  lessened  by  the  sides,'  being  multiplied  together,  the  square-root 
of  the  product  is  the  exact  area.* 

Example :     What  is  the  area  of  an  oblong,  two  sides  of  which  are  twelve ;  and  two,  fivef 

12 
Statement:       ,| 1,       Answer:    60,  the  gross  and  exact  area. 


12 
Example:     What  is  the  area  of  a  quadrilateral  having  two  equal  sides  thirteen,  the  base  four- 
teen, and  the  summit  four? 
4 

Statement:     l-y         y3        Answer:     117  the  gross  area. 


14 
;  Example:    Tell  the  area  of  a  quadrilateral  having  three  equal  sides  twenty-five,  and  base  thirty- 
nine? 

25 


Statement :  25/  \25        Answer :  800  the  gross  area. 


39 
Example  :    Tell  the  gross  area  of  a  trapezium,  of  which  the  base  is  sixty,  the  summit  twenty- 
five,  and  the  sides  fifty-two  and  thirty-nine  ? 

Statement :  52/  ^39        Answer :    1933|  the  gross  area.  Ch. 


60 

'  The  sides  of  the  quadrilateral  are  severally  subtracted  from  the  half  of  the  sum  in  all  four 
places  ;  but  the  sides  of  the  triangle  are  subtracted  in  three,  and  the  fourth  remains  as  it  stood.  Ch. 

*  Examples  as  above.  Sides  of  the  equilateral  triangle  12;  the  sum  36;  its  half  set  down  four 
times  18,  18,  18,  18;  which  severally  lessened  by  the  sides  gives  6,  6,  6,  18.  The  product  of 
those  numbers  is  3888,  the  surd  root  of  which  is  the  exact  area. 

Sides  of  the  isosceles  triangle  10,  13,  13;  the  sum  36.  Its  half  18,  lessened  severally  by  the 
sides,  gives  5,  5,  8,  18.  The  product  whereof  is  3600.  The  square-root  of  this  is  the  exact  area, 
60. 

Sides  of  the  scalene  triangle  14,  13,  15.  HaJf  the  sum  21,  less  the  sides,  gives  7,  8,  6,  21. 
Product  7056 ;  the  root  of  which  is  the  exact  area  84. 

The  gross  area  of  the  equilateral  tetragon,  as  of  the  oblong,  is  the  same  with  the  exact  area. 

Sides  of  the  tetragon  with  two  equal  sides,  14,  13,  13,  4.  The  exact  area,  as  found  by  the  rule, 
is  108. 

Sides  of  the  tetragon  having  three  equal  sides,  39,  25,  25, 25.    Exact  area  768. 

Sides  of  the  trapezium  60,  52,  39,  25.     Exact  area  1764.  Ch. 

Putting  a  side  of  a  tetragon  equal  to  the  segment  of  the  base,  and  an  upright  equal  to  the  pel- 


Section  IV.  PLANE    FIGURE.  297 

22.  The  difference  of  the  squares  of  the  sides  being  divided  by  the  base, 
the  quotient  is  added  to  and  subtracted  from  the  base:'  the  sum  and  the 
remainder,  divided  by  two,  are  tlie  segments.  The  square-root,  extracted 
from  the  difference  of  the  square  of  the  side  and  square  of  its  corresponding 
segment  of  the  base,  is  the  perpendicular.' 

23.  In  any  tetragon  but  a  trapezium,  the  square-root  of  the  sum  of  the 
products  of  the  sides  and  countersides,'  is  tiie  diagonal.  Subtracting  from 
the  square  of  the  diagonal  the  square  of  half  the  sum  of  the  base  and  sum- 
mit, the  square-root  of  the  jemainder  is  the  perpendicular.* 


pendicular,  the  area  of  a  figure  is  represented  by  little  square  compartments  formed  by  as  many 
lines  as  are  the  numbers  of  the  upright  and  side.  Ch. 

'  The  bottom  (adhas)  or  lower  line  of  every  triangle  is  the  base  (bhli),  literally  ground.  The 
flanks  (p&rswa)  are  termed  the  sides  (bhuja).  In  an  equilateral  triangle,  or  in  an  equicrural  one, 
the  two  segments  of  the  base  are  equal.  In  a  scalene  triangle,  the  greater  segment  answers  to  the 
greater  side;  and  the  least  segment  to  the  least  side.  The  perpendicular  is  the  same,  computed 
from  either  side.  Ch, 

*  Example  :    An  isosceles  triangle,  the  base  of  which  is  ten,  and  the  sides  thirteen. 


Statement:   1^    \13     Answer:    Segments  5  and  5.    Perpendicular  12. 

10 
Example  :    A  scalene  triangle,  the  base  of  which  is  fourteen,  and  the  sides  thirteen  and  fifteen. 


Statement :   13/ 


15     Answer:    Segments  5  and  9-    Perpendicular  12.  Ch. 


14. 

The  segments  are  found  by  halving  the  sum  and  difference :  for  it  is  directed  in  a  subsequent 
rule  (§  23)  to  subtract  the  square  of  the  upright  from  that  of  the  diagonal ;  and  the  two  segments 
are  thence  deduced  by  the  rule  of  concurrence.  The  perpendicular  is  found  b}'  extracting  the 
square-root  of  the  remainder  when  the  square  of  the  side  has  been  subtracted  from  the  square  of 
the  diagonal ;  that  remainder  being  the  square  of  the  upright :  for  the  perpendicular  is  the  up- 
right, lb. 

'  The  opposite  sides ;  (See  §  21)  the  flanks,  and  the  base  and  summit.  Ch. 

*  Example :    An  equilateral  tetragon,  the  side  of  which  is  twelve. 
12 


Statement:   12 


12     Answer:  Diagonal,  the  surd  root  of  288.     Perpendicular  12. 


12 
The  example  of  an  oblong  is  similar. 


fm 


BRAHMEGUPTA. 


Chapter  XII. 


24.  Subtracting  the  square  of  the  upright'  from  the  square  of  the  diago- 
nal, the  square-root  of  the  remainder  is  the  side;  or  subtracting  the  square 
of  the  side,  the  root  of  the  remainder  is  the  upright :  the  root  of  the  sum  of 
the  squares  of  the  upright  and  side  is  the  diagonal. 


25.*  At  the  intersection  of  the  diagonals,  or  the  junction  of  a  diagonal 
and  a  perpendicular,  the  upper  and  lower  portions  of  the  diagonal,  or  of  the 
perpendicular  and  diagonal,  are  the  quotients  of  those  lines  taken  into  the 
corresponding  segment  of  the  base  and  divided  by  the  complement*  of  the 
segments.* 

Example  :    A  tetragon  having  two  equal  sides,  thirteen ;  and  the  base  fourteen,  and  summit  four. 

4 

Statement:   ly   \\l3     Answer:  Diagonal  15.     Perpendicular  12. 


14 
In  like  manner,  a  tetragon  with  three  equal  sides  :  (See  §  26.)  Ch. 

The  product  of  the  base  and  summit  is  equal  to  the  square  of  the  greater  segment  less  the  square 
of  the  least.  The  square  of  the  flaiilts  is  equal  to  the  square  of  the  perpendicular  added  to  the 
square  of  the  least  segment.  Their  sum  is  the  sum  of  the  squares  of  the  perpendicular  and  greater 
segments,  and  is  the  sum  of  the  squares  of  the  upright  and  side  :  and  its  square-root  conseejuently 
is  the  diagonal.  Half  the  sum  of  the  base  and  summit  is  the  greater  segment:  it  is  the  side.  Sub- 
tracting the  square  of  it  from  the  square  of  the  diagonal,  the  remainder  is  the  square  of  the  upright. 
Its  square-root  is  the  upright  termed  the  perpendicular.  lb. 

'  One  side  being  so  termed  (bcihu  or  bhvja),  the  other  is  called  upright.     It  matters  not  which. 

Ch. 

*  In  tetragons  having  two  or  three  equal  sides,  as  above  noticed,  to  show  the  method  by  which 
the  upper  and  lower  portions  of  the  diagonals,  as  divided  by  the  intersection  of  the  diagonals,  may 
be  found  :  and  the  upper  and  lower  portions  of  both  diagonal  and  perpendicular,  as  divided  by  the 
intersection  of  the  perpendicular  and  diagonal.  Ch. 

'  Swayuti,  the  line  which  joins  the  extremities  of  the  perpendicular  and  diagonal.  It  is  the 
greater  segment  of  the  base  or  complement  of  the  less  :  and  answers  to  Bha'scaua's  pii'Aa.     Lit. 

h  195. 

*  Example  :    The  tetragon  with  two  equal  sides  as  last  mentioned. 

4 


Statement : 


The  segment  of  the  base  7,  multiplied  by  the  diagonal  15,  makes  105. 


Divided  by  the  complement  9,  the  quotient  is  Ilf.    It  is  the  lower  portion  of  the  diagonal;  and 
subtracted  from  15,  leaves  the  upper  portion  3^-.     So  for  the  second  diagonal. 


Section^  IV. 


PLANE    FIGURE. 


299 


26.  The  diagonal  of  a  tetragon  other  than  a  trapezium,  being  multiphed 
by  the  flank,  and  divided  by  twice  the  perpendicular,  is  the  central  line;' 
and  so  is,  in  a  trapezium,  half  the  square-root  of  the  sum  of  the  squares  of 
opposite  sides.^ 

27.  The  product  of  the  two  sides  of  a  triangle,  divided  by  twice  the  per- 


In  like  manner,  at  the  intersection  of  the  perpendicular.  The  segment  5,  multiplied  by  the  dia- 
gonal 15,  and  divided  by  the  complement  pi  gives  the  lower  portion  8^;  which,  subtracted  from 
the  diagonal,  leaves  the  upper  portion  6f .  The  perpendicular  likewise,  12,  taken  into  the  corre- 
sponding segment  5,  makes  60 ;  which,  divided  by  the  complement  9j  yields  6f  the  lower  portion 
of  the  perpendicular:  and  this,  subtracted  from  12,  leaves  5^  the  upper  portion  of  it.  Ch. 

Put  the  proportion  '  If  the  entire  diagonal  be  hypotenuse  answering  to  a  side  equal  to  the  com- 
plement, what  will  be  the  hypotenuse  answering  to  a  side  equal  to  the  given  segment  of  the  base?' 
The  result  gives  the  portion  of  the  diagonal  below  the  intersection.     A  similar  proportion  gives 
the  segment  of  the  perpendicular.     Thus  the  lower  portions  are  found :  and,  subtracting  them  from 
the  whole  length,  the  remainder  is  the  upper  portion  of  the  diagonal  or  of  the  perpendicular.  lb. 
'  Hrldaya-rajju,  the  central  line,  is  the  semidiameter  of  a  circle  in  contact  with  the  angles.  Ch. 
In  an  equilateral  or  an  oblong  tetragon  it  is  equal  to  the  semidiagonal. — lb. 
Cona-sprig-^rfttajOi  bahir-vritta;  a  circle  in  contact  with  the  angles ;  an  exterior  circle:  one  cir- 
cumscribed. 

*  Example:  The  tetragon  with  two  equal  sides,  as  last  noticed. 
4 

The  diagonal  15,  multiplied  by  the  side  13,  is  195:  divided  by 
13/     \  /     \13  twice  the  perpendicular,  the  quotient  is  8  -J^;  the  length  of  the 

central  line. 


Example:  The  tetragon  with  three  equal  sides  before  exhibited  (§  21). 

25 

Diagonal  40,  multiplied  by  the  side  25,  makes  1000; 

which,  divided  by  the  perpendicular  doubled,  gives  the 

central  line  20|. 


Statement:  "o 


Example:  The  trapezium  of  which  the  base  is  sixty,  the  summit  twenty-five,  and  the  sides  fifty- 
two  and  thirty-nine. 

The  squares  of  the  base  and  summit  60  and  25  are  3600  and 
625.  The  sum  is  4225;  its  root  65:  the  half  of  which  ^ 
is  the  central  line.  Or  the  squares  of  the  flanks  52  and  39 
are  2704  and  1521 ;  the  sum  of  which  is  4225;  and  half 
the  root,  ^.  Ch, 

QQ2 


Statement:     52. 


300  BRAHMEGUPTA.  Chapter  XII. 

pendicular,  is  the  central  line:  and  the  double  of  this  is  the  diameter  of  the 
exterior  circle.* 

28.*  The  sums  of  the  products  of  the  sides  about  both  the  diagonals 
being  divided  by  each  other,  multiply  the  quotients  by  the  sum  of  the  pro- 
ducts of  opposite  sides;  the  square-roots  of  the  results  are  the  diagonals  in  a 
trapezium.' 

•  Example :  An  isosceles  triangle,  the  sides  of  which  are  thirteen,  the  base  ten,  and  the  perpen- 
dicular twelve. 

-„  /  \  ,a      Product  of  the  sides  iSp;  divided  by  twice  the  perpendicular,  gives 
Statement:       yJ\{  the  central  line  Zj^^.*  Ch. 

10 

Let  twice  the  perpendicular  be  a  chord  in  a  circle,  the  semidiameter  of  which  is  equal  to  the 
diagonal.  Then  this  proportion  is  put :  If  the  semidiameter  be  equal  to  the  diagonal  in  a  circle  in 
which  twice  the  perpendicular  is  a  chord,  what  is  the  semidiameter  in  one  wherein  the  like  chord 
is  equal  to  the  flank  f  The  result  is  the  semidiameter  of  the  circumscribed  circle,  provided  the 
flanks  be  equal.  But,  if  they  be  unequal,  the  central  line  is  equal  to  half  the  diagonal  of  an 
oblong  the  sides  of  which  are  equal  to  the  base  and  summit ;  or  half  the  diagonal  of  one,  the  sides 
of  which  are  equal  to  the  flanks.     It  is  alike  both  ways.  lb. 

For  the  triangle  the  demonstration  is  similar;  since  here  the  diagonal  is  the  side.  lb. 

*  This  passage  is  cited  in  Bha'scara's  lAMvati,  §  1£)0. 

'  Example  :  A  tetragon  of  which  the  base  is  sixty,  the  summit  twenty-five,  and -the  sides  fifty- 
two  and  thirty-nine. 

Statement:  /    v/\         The  upper  sides  about  the  greater  diagonal  are  39  and  25;  the 


60 

product  of  which  is  975.  The  lower  sides  about  the  same  are  6o  and  52  ;  and  the  product  3120. 
The  sum  of  both  products  4095.  The  upper  sides  about  the  less  diagonal  are  25  and  52 ;  the 
product  of  which  is  1300.  The  lower  sides  about  the  same,  60  and  39;  and  the  product  2340. 
The  sum  of  both  3640.  These  sums  divided  by  each  other  are  f  gf^  and  f^4^,  or  abridged  ^  and  §. 
The  product  of  opposite  sides  60  and  25  is  1500;  and  of  the  two  others  52  and  39  is  2028:  the 
sum  of  both,  3528.  The  two  foregoing  fractions,  multiplied  by  this  quantity,  make  3969  and 
3136;  the  square-roots  of  which  are  63  and  56,  the  two  diagonals  of  the  trapezium.  Ch. 

This  method  of  finding  the  diagonals  is  founded  on  four  oblongs.  lb. 

The  brief  hint  of  a  demonstration  here  given  is  explained  by  Gan'b's'a  on  L'Mvat't,  §  I91.     Two 
triangles  being  assumed,  the  product  of  their  uprights  is  one  portion  of  a  diagonal,  and  the  pro- 

*  The  tnauuscript  here  exhibits  8}  :  but  is  manifestly  corrupt:  u  is  the  text  of  the  rule  and  in  part  the  comment  on  it. 


I 


Section  IV. 


PLANE    FIGURE. 


301 


duct  of  their  sides  is  the  other;  as  before  shown.  (Deni.  of  §  191 — 2.)  The  two  sides  on  the  one 
part  of  the  diagonal  are  deduced  from  the  reciprocal  multiplication  of  the  hypotenuses  of  the  as- 
sumed triangles  by  their  uprights:  and  the  product  of  ihe  sides  is  consequently  equal  to  the  pro- 
duct of  the  uprights  taken  into  the  product  of  the  hypotenuses.  So  the  product  of  the  two  sides 
on  the  other  part  of  the  diagonal,  resulting  from  the  reciprocal  multiplication  of  the  hypotenuses 
by  the  sides  of  the  assumed  triangles,  is  equal  to  the  product  of  the  sides  of  the  triangles  taken  into 
the  product  of  their  hypotenuses.  Therefore  the  sum  of  those  products  of  the  sides  of  the  tra- 
pezium is  equal  to  the  diagonal  multiplied  by  the  product  of  the  hypotenuses.  The  sides  about 
the  other  diagonal  are  formed  by  the  upright  of  one  triangle  and  side  of  the  other  reciprocally 
multiplied  by  the  hypotenuses.  Their  product  is  equal  to  the  product  of  the  reciprocal  upright 
and  side  taken  into  the  product  of  both  hypotenuses.  Hence  the  sum  of  the  products  is  equal  to 
the  diagonal  multiplied  by  the  product  of  the  hypotenuses.  Therefore  dividing  one  by  the  other, 
and  rejecting  like  dividend  and  divisor  (i.  e.  the  product  of  the  hypotenuses),  there  remain  the 
diagonals  divided  by  each  other.  Now  the  sum  of  the  products  of  the  multiplication  of  opposite 
sides  is  equal  to  the  product  of  the  diagonals  [as  will  be  shown].  Multiplying  this  by  the  fractions 
above  found,  and  rejecting  equal  dividends  and  divisors,  there  remain  the  squares  of  the  diagonals: 
and  by  extraction  of  the  roots  the  diagonals  are  found.  Now  to  show,  that  the  sum  of  the  pro- 
ducts of  opposite  sides  is  equal  to  the  product  of  the  diagonals  :  the  three  sides  of  each  of  the  as- 
sumed triangles  being  multiplied  by  the  hypotenuse  of  the  other,  two  other  rectangular  triangles 
are  formed :  and  duly  adapting  together  the  halves  of  these,  a  figure  is  constituted,  the  sides  of 
which  are  equal  to  the  uprights  and  sides  of  the  two  triangles.  It  is  the  very  trapezium  ;  and  its 
area  is  the  sum  of  the  areas  of  the  triangles. 


4b? 
3 


12 


13 


Here  half  the  product  of  the  base  and  summit  is  the  area  of  one  triangle  ;  and  half  the  product  of 
the  flanks  is  so  of  the  other.  Therefore  half  the  sum  of  the  products  of  opposite  sides  is  the  area 
of  the  quadrangle.  Now  the  four  triangles  before  mentioned,  with  four  others  equal  to  them,  being 
duly  adapted  together,  these  eight  compose  an  oblong  quadrilateral  wiih  sides  equal  to  the  diagonals 
of  the  trapezium.     See  48  15  Half  the  area  of  the  oblong  or  product  of  the 


20 


36 


r 


^^^^-^ 

N^ 

^\ 

Ps 

20 


36 


48  15 

diagonals,  as  is  apparent,  will  be  the  area  of  the  trapezium.  It  is  half  the  sum  of  the  products  of 
opposite  sides.  Therefore  the  sum  of  the  products  of  the  opposite  sides  is  equal  to  the  product  of 
the  diagonals.  Gan. 


S02 


BRAHMEGUPTA. 


Chapter  XII. 


29.  Assuming  two  scalene  triangles*  within  the  trapezium,  let  the  seg- 
ments for  both  diagonals  be  separately  found  as  before  taught ;  and  then  the 
perpendiculars.* 

30 — 31.  Assuming  two  triangles  within  the  trapezium,  let  the  diagonals 
be  the  bases  of  them.'  Then  the  segments,  separately  found,  are  the  upper 
and  lower  portions  formed  by  the  intersection  of  the  diagonals.*    The  lower 


'  The  first  with  the  greater  diagonal  for  one  side,  and  the  least  flank  for  the  other  side ;  and  the 
second  having  the  least  diagonal  for  one  side,  and  the  greater  flank  for  the  other :  and  the  base  of 
the  tetragon  being  base  of  both  triangles.  Then  the  segments  are  to  be  separately  found  in  both 
triangular  figures,  by  the  rule  before  taught  (§  22);  and  then  find  the  two  perpendiculars  by  the 
sequel  of  the  rule.  Ch. 

*  In  the  unequal  tetragon  just  men- 


tioned, one  triangle  will  be  this     ^- 


and  the  other  this 


63, 


60 


In  the  one  the  difference  of  the  squares  of  the  sides  432,  divided  by  the  base,  gives  7  ^,  which 
subtracted  from,  and  added  to,  the  base,  makes  52  J  and  67  i-  These  divided  by  two  are  26f 
and  33  f  the  two  segments.  Whence,  taking  the  root  of  the  difference  of  the  squares  of  the  side 
and  its  segment,  the  greater  perpendicular  is  deduced  44  -J.  In  the  other  triangle,  the  two  seg- 
ments found  by  the  rule  are  9f  and  50^;  whence  the  least  perpendicular  comes  out  37  f.      Ch. 

'  The  greater  diagonal  is  the  base  of  one  ;  and  the  summit  and  greater  flank  are  its  sides.  The 
least  diagonal  is  the  base  of  the  other;  and  the  summit  and  least  flank  are  the  sides.  Ch. 

*  In  the  tetragon  just  now  instanced,  the  scalene  triangle  with  the  greater  diagonal  for  base  is  this 

^5- 


The  segments  of  its  base  as  found  by  the  rule  (f  22)  are  48  and  15.     These  are  respectively  the 
lower  and  upper  portions  of  the  greater  diagonal. 
The  scalene  triangle  with  the  less  diagonal  for  base  is    \~~;25  Here  the  segments,  by  the 


same  rule  (§  22),  are  36  and  20.    They  are  the  lower  and  upper  portions  of  the  least  diagonal. 

Or  find  the  segments  of  one  only  :  the  perpendicular,  found  by  the  rule  (§  22)  is  the  upper  por- 
tion of  the  second  diagonal :  and  subtracting  that  from  the  entire  length,  the  remainder  is  the 


Section  IV.  PLANE    FIGURE.  «0S 

portions  of  the  two  diagonals  are  taken  for  the  sides  of  a  triangle ;  and  the 
base  [of  the  tetragon]  for  its  base.  Its  perpendicular  is  the  lower  portion  of 
the  [middle]  perpendicular  of  the  tetragon  :  the  upper  portion  of  it  is  the 
moiety  of  the  sum  of  the  [extreme]  perpendiculars  less  the  lower  portion.^ 

32.*  At  the  intersection  of  the  diagonals  and  perpendiculars,  the  lower 
segments  of  the  diagonal  and  of  the  perpendicular  are  found  by  proportion : 
those  lines  less  these  segments  are  the  upper  segments  of  the  same.  So  in 
the  needle^  as  well  as  in  the  (pdia)  intersection  [of  prolonged  sides  and  per- 
pendiculars].* 

lower  portion  of  it.  Thus,  in  the  foregoing  example,  the  least  segment  in  the  first  triangle  is  15. 
Its  square  225,  subtracted  from  the  square  of  the  least  side  6"25,  leaves  400,  the  root  of  which  is 
20.  It  is  the  upper  portion  of  the  smaller  diagonal,  and  subtracted  from  the  whole  length  56, 
leaves  the  lower  portion  36.  Cii. 

'  In  the  same  figure,  the  scalene  triangle  composed  of  the  two  lower  segments  of  the  diagonals 
together  with  the  base  is  this  /t\  Here  the  perpendicular  found  by  the  rule 

60 
(§  22)  is  28  ^.     It  is  the  lower  portion  of  the  mean  perpendicular.     The  greatest  and  least  perpen- 
diculars being  4.4^  and  37  f,  the  moiety,  of  their  sum  is  41  -^.     This  is  the  length  of  the  entire 
mean  perpendicular.     Subtracting  from  it  its  lower  segment  the  residue  is  its  upper  segment  12  |. 

Ch. 

*  A  rule  to  find  the  upper  and  lower  portions  of  the  diagonals  and  perpendiculars  cut  by  the 
intersection  of  diagonals  and  perpendiculars,  within  a  trapezium  ;  also  the  lines  of  the  needle  and 
a  figure  of  intersection. 

'  Slichi,  the  needle  ;  the  triangle  formed  by  the  produced  flanks  of  the  tetragon.  The  section 
of  a  cone  or  pyramid. 

Pata,  samp6ta,  tripdta,  intersection ;  of  a  prolonged  side  and  perpendicular.  The  figure  formed 
by  such  intersection. 

♦  Example  :  In  a  trapezium  the  base  of  which  is  sixty ;  one  side  fifty-two ;  the  other  thirty- 
nine;  and  the  summit  twenty-five  :  the  greater  diagonal  si.xty-three;  the  less,  fifty-si.\  :  the  greater 
perpendicular  forty-five  less  one  fifth  ;  its  segments  of  the  base,  the  greatest  thirty-three  and  three- 
fifths,  the  least  twenty-six  and  two-fifths :  the  least  perpendicular  thirty-seven  and  four-fifths  ;  its 
segments  of  the  base,  greatest  fifty  and  two-fifths,  least  nine  and  three-fifths :  the  perpendicular 
passing  through  the  intersection  of  the  diagonals,  forty-one  and  three-tenths;  its  segments  of  the 
base,  greatest  thirty-eight  and  two-fifths,  least  twenty-one  and  three-fifths;  tell  the  upper  and 
lower  portions  of  the  perpendiculars,  the  intersections  [of  prolonged  sides  and  perpendiculars]  and 
the  needle. 


304 


BRAHMEGUPTA. 


Chapter  XII. 


Here  at  the  intersection  of  the  diagonals,  the  segments  of  the  greater  diagonal,  found  as  before 
(§  30),  are  48  and  15  ;  those  of  the  less  are  36  and  20. 


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03 


At  the  junction  of  the  greater  diagonal  and  greater  perpendicular;  the  proportion  is  as  diagonal 
sixty-three  to  the  complement*  fifty  and  two  fifths,  so,  to  the  segment  twenty-six  and  two-fifths, 
what?  or  rendered  homogeneous,  SAi  |  63  |  i-2-5.  |  .     Answer:   33.     It  is  the  lower  portion  of  the 

diagonal.  Again,  as  the  same  complement  is  to  the  least  perpendicular,  so  is  the  above  men- 
tioned segment  to  what  ?     Statement:     SA?  I  !A2  |  L?i  |      Answer:    19^.     It  is  the  lower  por- 

5  5  5 

tion  of  the  perpendicular.  Subtracting  these  from  the  whole  diagonal  63  and  entire  perpendicular 
44^,  the  remainders  are  the  upper  segments  of  the  diagonal  and  perpendicular;  30  and  25. 

Ne.Kt,  at  the  junction  of  the  less  diagonal  and  less  perpendicular :  as  the  complement  thirty-lhree 
and  three-fifths  is  to  the  diagonal  fifty-six,  so  is  the  segment  nine  and  three-fifths  to  what  ?  State- 
ment: 33f  I  56  I  9i  I  •  Answer:  l6,  the  lower  portion  of  the  diagonal.  So, putting  the  perpen- 
dicular for  the  middle  term,  the  lower  portion  of  the  less  perpendicular  comes  out  12^.  By  sub- 
traction from  the  entire  diagonal  and  perpendicular,  their  upper  segments  are  obtained  40  and  25. 

In  like  manner,  for  any  given  question,  the  solution  may  be  variously  devised  with  the  segment 
of  the  base  for  side,  the  segment  of  the  perpendicular  for  upright,  and  the  segment  of  the  diagonal 
for  hypotenuse. 

The  operation  on  the  needle  is  next  exhibited 


The  segments  of  the  base  on  either  side  of  the  perpendicular  let  fall  from  the  top  of  the  needle 
come  out  41  ^  and  18  -^.f  With  either  of  these  segments  the  mean  perpendicular  is  found  by 
proportion  :  if  the  least  segment  9f  give  the  least  perpendicular  37f ,  what  does  the  segment 
18  -^  give  ?  Answer  :  71  ^.  It  is  the  perpendicular  let  fall  from  the  summit  of  the  needle.  In 
the  same  manner,  with  the  greater  segment,  the  same  length  of  the  perpendicular  is  deduced. 

Next,  to  find  the  sides  of  the  needle  :  As  the  least  perpendicular  is  to  the  side  thirty-nine,  so  is 
the  middle  perpendicular  to  what  ?  Statement :  37  f  t  39  |  71  ^.  Answer  :  73  -f^.  Or  the  side 
may  be  found  from  the  segments  :  thus  g|  |  39  |  18  ■^^.     Answer ;  73  ^  as  before.    To  find  the 

•  Swayuti.    See  note  to  $ 25. 

t  The  text  relative  to  the  inetbod  of  finding  tliese  legmenti  it  irretrievably  corrupt;  and  has  been  therefore  omitted 
la  thi  version. 


Section  IV. 


PLANE    FIGURE. 


305 


greater  side:  As  the  greater  perpendicular  is  to  the  side  fifty-two,  so  is  the  perpendicular  of  the 
needle  to  what?  44f  |  52  |  7H^  |  .  Answer:  82-^.  Or  proportion  may  be  taken  with  the 
legments  of  the  base:   26f  |  52  |  41 -Jf  |  .     Answer:  82 -f^,  as  before.     See  figure  [as  above]. 

Now  to  find  the  intersections  [of  the  prolonged  sides  and  perpendiculars].  If  the  segment  of 
the  base  belonging  to  the  greater  perpendicular,  or  26 -j,  answer  to  that  perpendicular,  44 1^,  what 
will  the  segment  50  y  answer  to  ?  Answer:  85  3^,  the  perpendicular  prolonged  to  the  intersection. 
Again:  As  the  greater  perpendicular  44 1^  is  to  the  side  52,  so  is  the  perpendicular  of  the  inter- 
section 85^  to  what?  Answer  :  99-ht  the  side  of  the  figure.  In  like  manner  to  find  the  per- 
pendicular of  the  second  figure  of  intersection :  If  the  segment  of  the  base  appertaining  to  the  less 
perpendicular  answer  to  this  perpendicular,  what  does  the  segment  thirty-three  and  three-fifths 
correspond  to  ?  Answer:  132  3^,  the  perpendicular  of  second  figure.  To  find  the  side  of  the 
same  :  As  the  least  perpendicular  37  |-  is  to  the  side  39,  so  is  the  perpendicular  just  found  132  ^y 
to  what?  Answer:  1363,  the  side.  Or  it  may  be  found  from  the  segments.  Thus,  as  the  seg- 
ment answering  to  the  least  perpendicular,  9  J,  is  to  the  side  39,  so  is  the  segment  33  |-  to  what  ? 
Answer:  the  greater  side  136J  as  before.  See  figure  of  the  needle  with  the  intersections  and  per- 
pendiculars. 


Va* 

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60 

In  like  manner,  the  flank  intersections*  are  computed.  If  the  segment  appertaining  to  th» 
greater  perpendicular  26 1-  answer  to  that  perpendicular,  what  will  the  segment  60  correspond  to  ? 
Answer:  101 -f\.  To  find  the  side  of  the  same:  As  the  segment  of  the  base  for  the  greater  per- 
pendicular is  to  the  side  fifty-two,  so  is  the  segment  sixty  to  what?  26f  |  52  |  60  |  .  Answer: 
118-^.  So,  on  the  other  part:  If  the  segment  of  the  base  for  the  less  perpendicular  answer  to 
that  perpendicular,  what  will  the  segment  sixty  correspond  to?  9f  [  37^  |  60  |  .  Answer: 
236  4.  To  find  the  side:  As  the  least  segment  is  to  the  side  thirty-nine,  so  is  the  segment  sixty  to 
what?    9i  I  39  I  60.    Answer:     245 j.    See 


236J 


10>A 


*  Piritca-pita,  tbe  intersection  of  the  prolonged  flank  and  perpendicular  railed  at  the  eztramity  of  the  base. 

R  R 


906  B  R  A  H  M  E  GU  PT  A,  Chapter  XII. 

33.*  The  sum  of  the  squares  of  two  unalike  quantities  are  the  sides  of  an 
isosceles  triangle ;  twice  the  product  of  the  same  two  quantities  is  the  per- 
pendicular ;  and  twice  the  difference  of  their  squares  is  the  base.' 

34.  The  square  of  an  assumed  quantity  being  twice  set  down,  and  divided 
by  two  other  assumed  quantities,  and  the  quotients  jjeing  severally  added  to 
the  quantity  first  put,  the  moieties  of  the  sums  are  the  sides  of  a  scalene 
triangle :  from  the  same  quotients  the  two  assumed  quantities  being  sub- 
tracted, the  sum  of  the  moieties  of  the  differences  is  the  base.' 

35.*    The  square  of  the  side  assumed  at  pleasure,  being  divided  and  then 

In  the  top  above  tbe  summit  of  the  trapezium  A  a  distribution  of  the  figure  is  to 


be  in  like  manner  made  by  proportions  selected  at  choice. 

Since  every  where  the  segment  of  the  base  is  a  side,  the  corresponding  perpendicular  an  upright, 
and  the  flank  an  hypotenuse,  the  several  lines  above-stated  may  be  found  in  various  ways  by  the 
rule,  that  subtracting  the  square  of  the  upright  from  the  square  of  the  hypotenuse,  the  square-root 
of  the  residue  will  be  the  side ;  or  that  subtracting  the  square  of  the  side,  the  root  of  the  remainder 
will  be  the  upright. 

In  the  same  manner,  in  tetragons  with  two  or  three  equal  sides,  the  perpendicular  of  the  needle 
and  its  segments  of  the  base  are  to  be  found.  But  there  can  be  no  needle  to  an  equilateral  tetra- 
gon, nor  to  an  oblong.  Ch. 

■  *^"Tb  find  an  equicrural  triangle  ;  preparatory  to  sliowing  a  rectangular  one.  The  next  follow- 
ing rule  (§34')  is  for  finding  a  scalene  triangle.  An  equilateral  one  may  consist  of  any  quantity 
assumed  at  pleasure  for  the  side ;  since  all  the  sides  are  equal.  Ch. 

*  Example  :  Let  the  unalike  quantities  be  put  2  and  3.  Their  squares  are  4  and  9;  the  sum 
of  which  is  13;  and  the  sides  are  of  this  length.  Twice  the  product  is  12;  and  is  the  perpendi- 
lar.  Again,  the  squares  of  the  same  number  are  4  and  9'-  the  difference  is  5 ;  which  multiplied 
by  two  makes  10,  the  base.     [See  §  22.]  Ch, 

'  Example:  Let  12  be  assumed.  Its  square  is  144.  Put  the  two  numbers  6  and  8 ;  and 
severally  divide  :  the  quotients  are  24  and  18  :  which,  added  to  the  number  originally  put,  make 
36  and  30,  the  moieties  whereof  are  15  and  13,  the  two  sides.  The  same  quotients,  24  and  18, 
less  the  assumed  numbers  6  and  8,  make  18  and  10;  the  moieties  of  which  are  9  and  5:  and  the 
sum  of  these,  14,  is  the  base. — Ch.     [See  §  22.] 

♦  To  find  an  oblong  tetragon.    The  equilateral  tetragon  may  be  assumed  with  any  quantity: 

since  all  the  sides  arealike Ch.     The  subsequent  rules,  §36 — 38,  deduce  tetragons  with  two 

and  three  e(iual  sides  or  with  all  unequal. 


Section  IV.  PLANE    FIGURE.  $S)f 

lessened  by  an  assumed  quantity,  the  half  of  the  remainder  is  the  upright  of  an 
oblong  tetragon ;  and  this,  added  to  the  same  assumed  quantity,  is  the  diagonal.^ 

36.  Let  the  diagonals  of  an  oblong  be  the  flanks  of  a  tetragon  having 
two  equal  sides.  The  square  of  the  side  of  the  oblong,  being  divided  by  an 
assumed  quantity  and  then  lessened  by  it,  and  divided  by  two,  the  quotient 
increased  by  the  upright  of  the  oblong  is  the  base ;  and  lessened  by  it  is  the 
summit.'  »       , 

37'  The  three  equal  sides  of  a  tetragon,  that  has  three  sides  equal,  are  the 
squares  of  the  diagonal  [of  the  oblong].  The  fourth  is  found  by  subtracting 
the  square  of  the  upright  from  thrice  the  square  of  the  [oblong's]  side.  If  it 
be  greatest,  it  is  the  base;  if  least,  it  is  the  summit.' 

38.  The  uprights  and  sides  of  two  rectangular  triangles  reciprocally  mul- 
tiplied by  the  diagonals  are  four  dissimilar  sides  of  a  trapezium.  The  greatest 
is  the  base ;  the  least  is  the  summit ;  and  the  two  others  are  the  flanks.* 

'  Example:  Let  the  side  be  put  5.  Its  square  is  25,  which  divided  by  the  assumed  quantity 
one  makes  25;  and  subtracting  from  this  the  same  assumed  quantity,  half  the  remainder  is  12,  and 
is  the  upright.    This  added  to  the  assumed  divisor  is  the  diagonal  13. — Ch.     [See  §  21  and  23.] 

*  Example  :  If  the  diagonal  of  the  oblong  be  thirteen,  the  side  twelve  and  the  upright  five; 
what  tetragon  with  two  equal  sides  may  be  deduced  from  it?  The  diagonals  13  and  13  are  the! 
flanks.  The  square  of  the  side  12  is  144.  Divided  by  an  assumed  number  6,  it  gives  24;  from 
which  subtracting  the  number  put  6,  remains  18;  the  half  whereof  is  9-  This  with  the  upright 
5  added,  makes  14,  the  base.  Again,  the  same  moiety  9,  with  the  upright  5  subtracted,  leave* 
4,  the  summit. — Ch.     [See  §  21  and  23.] 

'  Example  :  Find  a  tetragon  with  three  equal  sides  from  an  oblong  the  diagonal  of  which  it 
five,  the  side  four,  and  upright  three.  Square  of  the  diagonal  25  ;  the  length  of  the  sides.  Square 
of  the  side  l6,  tripled,  is  48 :  from  which  subtracting  9.  the  square  of  the  upright  3,  the  remainder 
39  is  the  base.  Or  let  the  side  be  three  and  upright  four.  Square  of  the  side  tripled  is  27  ;  and 
subtracting  from  this  the  square  l6  of  the  upright  4,  the  remainder  11  is  the  summit. — Cii.  [See 
§21  and  26.] 

*  Example  :  In  one  oblong  the  diagonal  is  five,  the  upright  three,  and  the  side  four.  In  the 
second  the  diagonal  is  thirteen,  the  upright  twelve,  and  the  side  five.  The  uprights  and  sides  of 
each  of  the  two  rectangular  triangles,  viz.  12,  5.,  3,  and  4,  being  multiplied  by  the  diagonal  (hy- 
potenuse) of  the  other,  give  60,  25,  39  and  52.  Here  the  greater  number  60  is  the  base;  the 
least  25  is  the  summit;  the  remaining  two,  39  and  52,  are  the  flanks. — Cu,     [See  §21  and  28.] 


^V   V 


60 
R  B  2 


*)8  BRAIIMEGUPTA.  Chapter  XII. 

39.'  The  height  of  the  mountain,  taken  into  a  multiplier  arbitrarily  put, 
is  the  distance  of  the  town.  That  result  being  reserved,  and  divided  by  the 
multiplier  added  to  two,  is  the  height  of  the  leap.     The  journey  is  equal.* 

40.  The  diameter  and  the  scjuare  of  the  semidiamcter,  being  severally 
multiplied  by  three,  arc  the  practical  circumference  and  area.  The  square- 
roots  extracted  from  ten  times  the  squares  of  the  same  are  the  neat 
values.' 

•  Within  an  oblong  tetragon,  to  describe  a  figure  such,  that  the  sura  of  the  side  and  one  portion 
of  the  upright  may  be  equal  to  ih-j  diagonal  and  remaining  portion  of  the  upright :  «o  as  the  jour- 
neys may  be  equal.— Cii.  See  Lildvati,  §  154,  and  Vija-ganita,  §  126;  where  the  same  problem 
is  introduced  :  substituting,  however,  in  the  example,  a  tree,  an  ape  and  a  pond,  for  a  hill,  a 
wizard  and  a  town. 

*  Example :  On  the  top  of  a  certain  hill  live  two  ascetics.  One  of  them,  being  a  wizard,  travels 
through  the  air.  Springing  from  the  summit  of  the  mountain,  he  ascends  to  a  certain  elevation, 
and  proceeds  by  an  oblique  descent,  diagonally,  to  a  neighbouring  town.  The  other,  walking 
down  the  hill,  goes  by  land   to  the  same  town.     Their  journeys  are  equal.     I  desire  to  know  the 

■  distance  of  the  town  from  the  hill,  and  how  high  the  wizard  rose. 

This  being  proposed,  the  rule  applies ;  and  its  interpretation  is  this :  any  elevation  of  the  moun- 
tain is  put;  and  is  multiplied  by  an  arbitrarily  assumed  multiplier:  the  product  is  the  distance  of 
the  town  from  the  mountain.  Then  divide  this  reserved  quantity  by  the  multiplier  added  to  two, 
the  quotient  is  the  number  of  yojanas  of  the  wizard's  ascent.  The  sum  of  the  hill's  elevatioi\  and 
wizard's  ascent  is  the  upright;  the  distance  of  the  town  from  the  mountain  is  the  side  :  the  square- 
root  of  the  sum  of  their  squares  is  the  diagonal  (hypotenuse)  :  it  is  the  oblique  interval  between  the 
town  and  the  summit  of  the  rise. 

Thus,  let  the  height  of  the  mountain  be  twelve.  This,  multiplied  by  an  arbitrarily  assumed  mul- 
tiplier four,  12  by  4,  makes  48.  It  is  the  distance  of  the  town  from  the  hill.  This  divided  by  the 
multiplier  added  to  two,  48  by  6,  gives  8.  It  is  the  ascent.  Here  the  upright  is  20 :  its  square 
is  400.     The  side  is  48  ;  the  square  of  which  is  2304.     The  sum  of  these  squares  is  2/04;  an* 

its  square-root  52.     The  semirectangle*  is  thus  found.         ;"- ..  Here  also  the  sum 

20  "■••4j? 

12  ■■•••... 


48 
of  the  side  and  lower  portion  of  the  upright  is  6o,  the  journey  of  one  of  the  ascetics:  and  the 
upper  portion  added  to  the  hypotenuse  is  that  of  the  other,  likewise  60. 

The  author  will  treat  of  rectangular  triangles  and  surd  roots,  in  the  chapter  on  Algebra  (ciittacd- 
JChy6yc[\J  under  the  rule,  which  begins,  "  Be  a  surd  the  perpendicular.  Its  square,  &c."  We  alsoi 
shall  there  expound  it.  Ch. 

'  Example  :  Of  a  circle,  the  diameter  whereof  is  ten,  what  is  the  circumference  i  and  how 
much  the  area  ? 

*  Ayatdrd'ha,  half  an  oblong, 
t  See  Brahn.  Alg.  $  36. 


Section  IV.  PLANE    FIGURE:    CIRCLE.  309 

41.  In  a  circle  the  chord  is  the  square-root  of  the  diameter  less  the  arrow 
taken  into  the  arrow  and  multiplied  by  four.'  The  square  of  the  chord  di- 
vided by  four  times  the  arrow,  and  added  to  the  arrow,  is  the  diameter.' 


Statement:      /     tn      \         Diameter  10,  multiplied  by  three,  30;   this  is  the  gross  circum- 


ference.     Semidiameter  5  :  its  square  25  ;  tripled,  75 ;  the  gross  area  for  practice. 

Diameter  10 :  its  square  100,  multiplied  by  ten,  1000.  The  surd  root  of  this  is  the  circum- 
ference of  a  circle  the  diameter  whereof  is  ten.  Square  of  the  semidiameter  25  :  This  again 
squared  and  decupled  is  6250.     Its  surd-root  is  the  area  of  the  circle.  Ch. 

'  Example:  Within  a  circle,  the  diameter  of  which  is  ten,  in  the  place  where  the  arrow  is 
two,  what  is  the  chord  ? 

Diameter  10  :  less  the  arrow  2  ;  remains  8.  This  multiplied  by  the  arrow  makes  l6;  which 
multiplied  by  4,  gives  6'4  :  the  square-root  of  which  is  8.     See  figure 

:8 a 


The  principle  of  the  rule  for  finding  the  square  of  the  chord  (in  the  construction  of  tabular  sines) 
is  here  to  be  applied.  But  the  square  is  in  this  place  multiplied  by  four,  because  the  entire  chord 
is  required.  Cn. 

*  Example  :  Chord  8.  Its  square  64,  divided  by  four  times  the  arrow  2,  viz.  8;  gives  the 
quotient  8  :  to  which  adding  the  arrow,  the  sum  is  10. 

Example  2d :  A  bambu,  eighteen  cubits  high,  was  broken  by  the  wind.  Its  tip  touched  the 
ground  at  six  cubits  from  the  root.     Tell  the  length  of  the  segments  of  the  bambu. 

Statement:  Length  of  the  bambu  18.  It  is  the  diameter  less  the  least  arrow.*  The  ground 
from  the  root,  to  the  point  where  the  tip  fell,  is  6 :  it  is  the  semichord.  Its  square  is  36.  This  is 
equal  to  the  diameter  less  the  arrow  multiplied  by  the  arrow.  Dividing  it  by  the  diameter  less  the 
arrow,  viz.  18,  the  quotient  is  2.  It  is  the  arrow.  Adding  this  to  the  diameter  less  the  arrow,  the 
sum  is  the  diameter,  20.  Half  of  this,  10,  is  the  semidiameter.  It  is  the  upper  portion  of  the 
bambu  and  is  the  hypotenuse.  Subtracted  from  eighteen,  it  leaves  the  upright,  or  lower  portion 
of  the  bambu,  8.  The  side  is  the  interval  between  the  root  and  tip,  6.  The  point  of  fracture  of 
the  bambu  is  the  centre  of  the  circle.     See  figure 


Example  3d  :     In  limpid  water  the  stalk  of  a  lotus  eight  fingers  long  was  to  be  seen.f  

That  visible  [portion  of]  stalk  is  the  smaller  arrow.    The  place  of  submersion,  24,  is  the  semi- 

•  What  is  termed  by  us  "  diameter  less  tlie  arrow,"  is  by  Arya-bhatta  denominated  the  greater  arrow.     For  he 
says,  '  In  a  circle  the  product  of  the  arrows  is  equal  to  the  square  of  the  semichord  of  both  arcs.'  Ca. 

t  The  remainder  of  the  passage,  in  which  the  qaestian  was  proposed,  is  wanting. 


310  BRAHMEGUPTA.  Chatter  XII. 

42.'     Half  tlie  difference  of  the  diameter  and  the  root  extracted  from  the 
difference  of  the  squares  of  the  diameter  and  the  chord  is  tl>e  smaller  arrow.* 

chord.  From  the  square  of  this  [semi-]chord  576  divided  by  the  smaller  arrow  8,  the  quotient  72 
is  obtained,  which  is  the  greater  arrow.  The  sum  of  both  arrows,  viz.  80,  is  the  diameter  of  the 
circle.  Its  half  is  40,  the  semidiameter.  It  is  the  hypotenuse,  and  is  the  length  of  the  stalk  of 
lotus.  Subtracting  the  smaller  arrow,  the  remainder  is  the  depth  of  water  and  is  the  upright  52. 
The  side  is  the  space  to  the  place  of  submersion  and  is  the  semichord.     See 


Example  4th  :  A  cat,  sitting  on  a  wall  four  cubits  high,  saw  a  rat  prowling  eight  cubits  from 
the  foot  of  the  wall.  The  rat  too  perceived  the  puss  and  hastened  towards  its  abode  at  the  foot  of 
the  wall ;  but  was  caught  by  the  c&t  proceeding  diagonally  an  equal  distance.  In  what  point 
within  the  eight  cubits  was  the  rat  caught ;  and  what  was  the  distance  they  went  ?  Tell  me,  if  thou 
be  conversant  with  computation  concerning  circles. 

Statement :  Height  of  the  wall  4.  Distance  to  which  the  rat  had  gone  forth  8.  These  are 
semichord  and  greater  arrow.  The  square  of  the  semichord,  l6,  being  divided  by  the  greater 
arrow  8,  the  quotient  is  the  smaller  arrow  2.  The  sura  of  both  arrows  is  the  diameter  10.  Its 
half  is  the  semidiameter  5.  It  is  the  rat's  return.  Subtracting  it  from  the  eight  cubits,  the  re- 
mainder is  the  interval  between  the  foot  of  the  wall  and  point  of  capture,  or  upright  3.  The  side 
is  4.  The  root  of  the  sum  of  their  squares  is  the  hypotenuse  :  it  is  the  cat's  progress,  and  is  equal 
to  the  rat's  progress  homewards.* 

Let  the  figure  be  exhibited  as  before.    In  the  centre  of  it  is  the  place  of  capture. 


In  like  manner  other  examples  may  be'shown  for  the  instruction  of  youth.  Else  all  this  is  ob* 
vious,  when  the  relation  of  side,  upright  and  hypotenuse  is  understood.  Ch. 

'  The  chord  and  diameter  being  given,  to  find  the  smaller  arrow.  And,  when  two  circles,  the 
diameters  of  which  are  known,  cut  each  other,  to  find  the  two  arrows.  Ch. 

*  Example:  Chord  8.  Its  square  64.  Diameter  10.  Its  square  100.  Difference  36.  Its 
root  6.  Subtracting  this  from  the  diameter  10,  the  moiety  of  the  remainder  is  2  and  is  the  smaller 
arrow. 

The  same  figure  is  here  contemplated.  Within  it  let  an  oblong  be  inscribed,  with  the  chord  for 
its  side,  the  diflerence  between  the  diameter  and  twice  the  arrow  for  its  upright,  and  the  entire 
diameter  for  its  diagonal.    It  is  this      -^^32:^^        Here,  the  square-root  of  the  diflerence  between 


the  squares  of  the  diameter  and  chord  is  equal  to  the  root  of  the  residue  of  subtracting  the  square 
of  the  side  from  the  square  of  the  diagonal,  and  is  the  upright :  and,  that  being  taken  from  the 
diameter,  two  portions  remain  equal  to  the  smaller  arrow,  one  at  either  extremity.  Hence  the 
rule  §  42.     Let  all  this  be  shown  on  the  figure.  Ch. 

•  The  three  last  instances  are  imitated  in  Bhascara's  IMvati,  J  148—153,  and  Vlj.-gim.  J  U4— U5  and  139. 


Section  IV.  PLANE    FIGURE:    CIRCLE.  311 

The  erosion'  being  subtracted  from  both  diameters,  the  remainders,  multi- 
pHed  by  the  erosion  and  divided  by  the  sum  of  the  remainders,  are  the  arrows.* 

43.'  The  square  of  the  semichord  being  divided  severally  by  the  given 
arrows,  the  quotients,  added  to  the  arrows  respectively,  are  the  diameters.* 
The  sum  of  the  arrows  is  the  erosion :  and  that  of  the  quotients  is  the  residue 
of  subtracting  the  erosion.' 

'  Gr^a,  the  erosion,  the  raorcei  bitten ;  the  quantity  eclipsed. 

Samparca,  intersection. 

*  Example  :  The  measure  of  Rdhu  is  fifty-two ;  that  of  the  moon,  twenty-five :  the  erosion  is 
seven. 

Diameters  52  and  25.  Remainders  after  subtracting  the  erosion  45  and  18.  These  multiplied 
by  the  erosion,  make  315  and  126:  which,  divided  by  the  sum  of  the  residues  63,  give  5  and  2, 
for  the  segments  cut  by  a  chord  passing  through  the  points  of  intersection  of  the  circles.  The 
arrow  of  Rdhu  is  two  ;  that  of  the  moon  five.     See 


Here  the  erosion  is  the  profit;  and  the  diameters  less  the  erosion,  are  the  contributions;  and  the 
segments  are  found  by  the  rule,  §  l6.  The  greater  quotient  belongs  to  the  least  circle;  and  the 
less  quotient,  to  the  greater  circle.  Ch. 

^  In  the  liite  case  of  the  intersection  of  two  circles,  the  chord  and  arrows  being  known,  to  find 
the  diameters :  And,  the  diameter  and  arrows  being  given,  to  deduce  the  quantity  eclipsed  and 
the  residue.  Ch. 

♦  E.xample  :     The  intersection  of  the  circles  last  mentioned. 

Chord  20.  Its  half  10  :  the  square  of  which  is  100.  Divided  by  the  two  arrows  severally,  viz. 
5  and  2  ;  the  quotients  are  20  and  50  :  which,  with  the  arrows  respectively  added,  make  25  and 
52.    They  are  the  diameters.     See  foregoing  diagram. 

Demonstration  :  So  much  as  is  the  square  of  the  semichord,  is  the  square  of  greater  and  less 
arrows  multiplied  together.  The  quotient  of  the  division  thereof  by  the  less  arrow  is  the  greater 
arrow ;  and  the  sum  of  the  greater  and  less  arrows  is  the  diameter,  as  even  the  ignorant  know. 

Ch. 

'  Example  :  The  arrows  just  found,  5  and  2.  Their  sum  is  7.  It  is  the  erosion  or  quantity 
eclipsed.  The  quotients  20  and  50.  Their  sum  70.  It  is  the  residue,  subtracting  the  erosion 
[from  the  sum  of  the  diameters]. 

The  principle  is  here  obvious.  Ch. 


(     312     ) 


SECTION  V. 


EXCAVATIONS. 

44.  The  area  of  the  plane  figure,  multiplied  by  the  depth,  gives  the  con- 
tent of  the  equal  [or  regular]  excavation;  and  that,  divided  by  three,  is  the 
content  of  the  needle.' 

In  an  excavation  having  like  sides  [length  and  depth]  at  top  and  bottom, 
[but  varying  in  depth,]  the  aggregates*  [or  products  of  length  and  depth  of 
the  portions]  being  divided  by  the  common  length,  [and  added  together,]  give 
the  mean  depth.' 

"  45 — 46.     The  area,  deduced  from  the  moieties  of  the  sums  of  the  sides  at 
top  and  at  bottom,  being  multiplied  by  the  depth,  is  the  practical  measure 


'  Example:    Tell  the  content  of  a  well,  in  which  the  sides  are  ten  and  twelve,  alike  above  and 
below,  and  the  depth  five. 


Statement: 


Here  the  area  is  120:  which,  multiplied  by  the  depth  5,  gives 
the  content  in  cubic  cubits,  600. 


In  the  like  instance,  if  the  well  terminate  in  a  point,  the  foregoing  divided  by  three  gives  200, 
the  content  of  the  needle  or  pyramid. 

*  Aicya,  lit.  aggregate  :  explained  by  the  commentator  the  product  of  the  length  and  depth  of 
the  portions  or  little  excavations  ditfering  in  depth. 

Ecigra,  the  whole  of  the  long  side  which  is  subdivided, 

Snma-rajju,  equal  or  mean  string:  the  mean  or  equated  depth   (sama-bedtha). 

'  pxample:  A  well  thirty  cubits  in  length,  and  eight  in  breadth,  comprises  within  it  five  por- 
tions of  excavation,  by  which  the  side  is  subdivided  into  parts  measuring  four,  &c.  [up  to  eight]. 
The  depth  severally  measures  nine,  seven,  seven,  three  and  two.  Say  quickly  wha't  is  the  mean 
ttring  [mean  depth]  of  the  excavations. 


) 


k 


Section  V. 


EXCAVATIONS. 


513 


of  the  content.*  Half  the  sum  of  the  areas  at  top  and  at  bottom,  multiplied 
by  the  depth,  gives  the  gross  content.  Subtracting  the  practical  content 
from  the  other,  divide  the  difference  by  three,  and  add  the  quotient  to  the 
practical  content,  the  sum  is  the  neat  content.- 


Statement : 


30 


9 
4 

7 
5 

\ 

37 

2  e   L 

y^ 

^ 

^ 


Here  the  aggregates  in  their  order  are 


36,  35,  42,  21,  16.  These,  divided  by  the  whole  length  30,  give  1%  ^  %%  %\  |f ;  which 
added  together  mnke  '^^  ;  the  quotient  is  the  mean  depth  5.  The  area  of  the  plane  figure  240, 
multiplied  by  that,  is  1200.  It  is  the  solid  content  of  the  entire  excavation.  It  may  be  proved  by 
adding  together  the  several  contents  of  the  parts :  viz.  of  the  1st,  288;  of  the  2d,  280 ;  of  the  3d, 
336 ;  of  the  4th,  l6s  ;  of  the  5th,  128  :  total  1200. 

'  Vyavahdrka,  designed  for  practical  use. 

Autra,  gross.  [The  etymology  and  proper  sense  of  the  term  are  not  obvious  j  and  are  unex- 
plained.] 

Sucskma,  neat,  or  correct. 

*  E.tample:  A  square  well,  measured  by  ten  cubits  at  the  top  and  by  six  at  the  bottom,  is 
dug  thirty  cubits  deep.     Tell  me  the  practical,  the  gross,  and  the  neat  contents. 

Here  the  side  at  the  lop  is  10  ;  that  at  the  bottom  is  6.  The  sum  of  these  is  \6;  its  moiety  8. 
The  same  in  the  other  directions,  8.  The  area  with  these  sides  is  64;  which,  multiplied  by  the 
depth  30,  makes  192O.     It  is  the  practical  content. 

Sides  at  the  top  10,  10.  Area  deduced  from  them  100.  Sides  at  the  bottom  6,  6,  Area  de- 
duced from  these  36.  Sum  of  the  areas  136.  Its  half  68;  multiplied  by  the  depth  30,  makes 
2040.     It  is  the  gross  content. 

Subtracting  the  practical  content  from  this,  the  difference  is  120.  Divided  by  three,  it  gives 
40.    Adding  this  to  the  practical  content  J 920,  the  sum  is  i960  the  neat  content. 


s  s 


:i  ■ 


(     314    ) 

SECTION  VI. 


STACKS.' 

47.  The  area  of  the  form  [or  section]*  is  half  the  sum  of  the  breadth  at 
bottom  and  at  top  muhiphed  by  the  height :  and  that  multipUed  by  the 
length  is  the  cubic  content :  which  divided  by  the  soHd  content  of  one  brick, 
is  the  content  in  bricks.' 

'  There  is  iw  difference  in  principle  between  the  measure  of  excavations  and  of  stacks ;  unless 
that  what  is  there  depth  is  here  height.     Every  thing  else  is  alike  in  both.  Ch. 

*  Acriti :  the  form  or  shape  of  the  wall,  as  it  appears  in  one  cubit's  length,  according  to  it» 
height  and  the  thickness  at  bottom  and  top. — Ch.     Section  of  the  wall. 

'  Example  1st :  Tell  the  content  of  a  stack  which  is  a  hundred  cubits  in  length  ;  five  in  thick- 
ness at  bottom,  and  three  at  top ;  and  seven  high. 

3 
Statement: 


7^ 


3 


5  100 

Breadth  at  top  3;  at  bottom  5.  Sum  8.  Its  half  4,  multiplied  by  7,  is  28:  which,  multiplied 
by  the  length  100,  makes  2800.  So  many  are  the  cubic  contents  in  the  wall.  The  dimensions  of 
a  brick  may  be  arbitrarily  assumed.  Say  a  cubit  long;  half  of  one  broad  ;  and  a  sixth  part  thick. 
Statement:  i  J  i-  Product-^.  The  whole  cubic  amount  2800,,  divided  by  that,  gives  3360O 
for  the  number  of  bricks. 

Example  2d:  A  sovereign  piously  caused  a  quadrangle  to  be  built  for  a  college,  the  wall 
measuring  a  hundred  cubits  without  and  ninety-six  within,  and  seven  high,  with  a  gate  four  by 
three,  and  wickets  half  as  big  on  the  sides.     How  many  bricks  did  it  contain  ? 

100 

Here  the  area  of  the  exterior  figure  is  10,000i 

that  of  the  interior  one  92l6.  The  difference 
is  784.  It  is  the  area  of  the  figure  covered  by 
the  walls.  Multiplied  by  the  height  7,  it 
gives  the  content  5488;  from  which  subtract- 
ing the  gates  36,  the  remainder  is  the  exact 
cubic  content  5452.  Dividing  this  by  the 
content  of  a  brick  -jV,  the  quotient  is  the  num- 
ber of  bricks  65424, 


Statement: 


(     315     ) 

SECTION  VII. 


SAW. 

48 — 49.  The  product  of  the  length  and  thickness  in  fingers,  being  mul- 
tiplied by  the  number  of  sections  and  divided  by  forty-two,  is  the  measure  in 
cishcangulas.'  That  quotient,  divided  by  ninety-six,  gives  the  work,'  if 
the  timber  be  Mca  or  the  like;*  but,  if  it  be  sdlmali,  the  divisor  is  two  hun- 
dred; if  vijaca,  a  hundred  and  twenty;  if  sola,  saraiia  and  the  rest,  one 
hundred;  if  sapta-viddru,  sixty-four.* 

'  Ayima,  breadth,  or  rather  (dairghya)  length.  Vistara,  width,  or  rather  (ghanatvia)  thick- 
ness. Mdrga,  the  way  or  path  of  the  saw  ;  the  section.  Ciskcangula,  a  technical  term  in  use  with 
artisans.     Carman,  the  work  ;  that  is,  the  rate  of  the  workman's  pay  :  a  technical  use  of  the  term. 

Ch. 

*  Sdca,  Tectona  grandis.  Salmali,  Bombax  heptaphyllum:  it  is  the  softest  wood  used  for  tim- 
ber. Vijaca,  Citrus  medica.  Sdla,  Shorea  robusta.  Saraiia,  same  with  Sarah?  Pinus  longi- 
folia.     Vidaru,  not  known.     C'hadira,  Mimosa  Catechu  ;  the  hardest  wood  employed  as  timber. 

The  following  passage  of  Arya-bhat'ta  is  cited  by  Gan'esa  in  his  commentary  on  the  LUavat'i. 
'  The  product  of  the  breadth  [or  length]  and  thickness,  in  fingers,  being  multiplied  by  the  intended 
sections,  and  divided  by  five  hundred  and  seventy-six,  the  quotient  is  the  (p'hala)  superficial 
measure  of  the  cutting,  provided  the  timber  be  C'hadira  (Mimosa  catechu).  If  the  wood  be  Sriparnl 
(  ),  Sdcaca  (Tectona  grandis),  &e.  the  divisor  should  be  put  three  hundred  and  fifty  ; 

if  the  wood  be /am6«  (Eugenia  Jamboo),  Fya  (Citrus  medica),  Cadamba  (Nauclea  orientalis  and 
Cadamb),  or  Amli  (Tamarindus  indica),  it  should  be  twenty  less  than  four  hundred.  The  divisor 
should  be  two  hundred  and  fifty,  if  the  timber  be  Sdla,  Antra  and  Sarala  (Shorea  robusta,  Mangi- 
fera  indica  and  Pinus  longifolia).  If  it  be  Salmali  (Bombax  heptaphyllum),  &c.  the  divisor  is  two 
hundred.     Money  is  to  be  paid  according  to  the  divisor.' 

*  Example  :  A  seasoned  timber  of  (Vijdca)  citron  wood,  ten  cubits  in  length  and  six  fingers  in 
width  [thickness],  is  sawed  in  seven  sections.  Say  what  is  the  price  of  the  labour,  if  the  rate  of 
work  be  eight  paiia.i. 

Statement:     -j  ^      Product  of  tlie  thickness  6,  by  the  length  240,  is  1440. 


240 
Multiplied  by  7,  it  makes  10080  ;  which,  divided  by  forty-two  (42),  gives  240.     These  are  cish- 
cangulas.    The  timber  being  wood   of  the   yija  tree,  that  is  divided  by  one  hundred  and  twenty. 
The  quotient  is  the  quantity  of  the  work,  2.     Multiplierl  by  the  rate  of  the  pay,  viz.  8,  the  product 
is  the  number  oi  ■paiias  ifi.    This  amount  is  to  be  paid  to  the  artisan.  Ch. 

s  s  2 


(    316    ) 
SECTION  VIII. 


MOUNDS    OF  GRAIN. 

50.  The  ninth  part  of  the  circumference  is  the  depth  [height]  in  the  case 
of  bearded  com;  the  tenth  part,  in  that  of  coarse  grain;  and  the  eleventh, 
in  that  of  fine  grain.'  The  height,  multiplied  by  the  square  of  the  sixth 
part  of  the  circumference,  is  the  content.* 

51.  The  circumference  of  a  mound  resting  against  the  side  of  a  wall,  oi 
within  or  without  a  corner,  is  multiplied  by  two,  by  four,  or  by  one  and  a 
third;  and,  proceeding  as  before,  the  content  is  found;  and  that  is  divided 
by  the  multiplier  which  was  employed. 

'  S&cin,  bearded- com :  viz.  rice,  as  sliasitic^  and  Ait  rest. 

St'hula,  coarse  grain  :  barley,  &c. 

Aiiu,  fine  grain  :  mustard  and  the  like.  Cir; 

*  The  content,  as  thus  found,  is  the  number  of  solid  cubits;  (the  circumference  having  beea 
taken  with  the  cubit:)  and  thence  the  number  of  prast'/tas  is  to  be  deduced, by  the  rule  of  three, 
According  to  the  proportion  of  tlie  cubit  to  the  particular /jras^'Ao  in  use. — Ch.  It  is  the  content 
in  solid  cubits  or  c'hdns  of  Magad'ha. — Gatl.  sir.  Ch.  12. 

'  Example  :  What  is  the  content  of  a  rooiind  of  rice  upon  level  ground,  tJ>e  circumference 
being  thirty-six  ? 

Statement :  Circum.  36.  Its  ninth  part  4,  This  is  the  height  of  the  mound.  The  sixth  part 
of  the  circumference  of  the  mound  is  6 ;  its  square  is  36  :  multiplied  by  the  height,  it  makes  144, 
the  content  of  the  mound  in  cubits. 

Example  2d  :     A  mound  of  barley,  the  circumference  of  which  is  thirty  ?      Answer:  75. 

Example  3d  :     A  mound  of  mustard  see<l,  sixty-six  cubits  in  circumference?    Answer :  726. 

Example  4th  :     A  mound  of  rice  resting  against  a  wall,  and  measuring  eighteen  ?  ^ 

18  doubled  is  36.     With  this  circumference  the  content  found  as  before  is  144;  which,  divided  ^] 

by  the  particular  multiplier  2,  gives  72,  the  solid  content  in  cubits  of  the  portion  of  a  mound. 

Example  5th  :  A  mound  of  rice  resting  against  the  outer  angle  of  a  wall  and  measuring  twenty- 
seven  ? 

27  multiplied  by  one  and  a  third  makes  36,  the  circumference.  Hence  the  content  144  ;  which, 
divided  by  the  particular  multiplier  f ,  gives  lOS,  the  content  of  a  mound  that  is  a  quarter  less  than 
a  full  one. 


Shaihtiea  or  Shatti ;  volg.  Su'ti  (Hind)  :  so  named  because  it  U  sown  and  reaped  in  siity  da^ s.     Or^za  sativn ;  Tur. 


♦ 


(     317    ) 


SIC 


SECTION  IX. 


MEASURE   BY  SHADOW. 

52.'  The  half  clay  being  divided  by  the  shadow  (measured  in  lengths  of 
the  gnomon)  added  to  one,  the  quotient  is  the  elapsed  or  the  remaining 
portion  of  day,  morning  or  evening.  The  half  day  divided  by  the  elapsed 
or  remaining  portion  of  the  day,  being  lessened  by  subtraction  of  one,  the 
residue  is  the  number  of  gnomons  contained  in  the  shadow.* 


.53.'  The  distance  between  the  foot  of  the  light  and  the  bottom  of  the 
gnomon,  multiplied  by  the  gnomon  of  given  length,  and  divided  by  the  dif- 
ference between  the  height  of  the  light  and  the  gnomon,  is  the  shadow.* 

•  To  find  the  time  from  the  shadow  ;  and  the  shadow  from  the  time.  Cti. 

*  This  rule  being  useless,  no  example  is  given.  It  does  not  answer  for  finding  either  the  shadow 
or  the  time,  in  a  position  even  equatorial ;  but  has  been  noticed  by  the  author  in  this  place,  copying 
earlier  writers  of  treatises  on  computation,  Cii. 

See  the  concluding  chapter  of  Skid'hara's  Gariila-sura,  where  the  same  rule  is  given,  and 
examples  of  it  subjoined. 

'  Given  the  length  of  the  gnomon  standing  at  a  known  distance  from  the  foot  of  a  light  in  a 
known  situation,  to  find  the  shadow.  Ch. 

♦  E.xamplc  :  The  height  of  the  light  to  the  tip  of  the  flame  is  a  hundred  fingers.  [The  distance 
a  hundred  and  ten.     The  gnomon  twelve.*] 

1 10,  multiplied  by  the  gnomon  12,  is  1320.  Subtracting  the  gnomon  12  from  the  height  100,  the 
remainder  is  88.  Dividing  by  this,  the  quotient  is  15,  the  shadow  of  a  gnomon  twelve  fingers 
high. 

Here  the  rule  of  three  terms  is  applicable  :  if  an  upright  equal  to  the  difference  of  the  two 
heights  answer  to  a  side  equal  to  the  interval  of  ground  between  the  foot  of  the  light  and  the 
jjjiomon,  what  will  answer  to  the  given  gnomon  ?     See 

100 


125  15 

•  Tbc  text  u  deficient :  but  u  aupplied  by  the  operation  in  the  ipqael. 


318 


BRAHMEGUPTA. 


Chapter  XII. 


54.'  The  shadow  multiplied  by  the  distance  between  the  tips  of  the 
shadows  and  divided  by  the  difference  of  the  shadows,  is  the  base.  The 
base,  multiplied  by  the  gnomon,  and  divided  by  the  shadow,  is  the  height 
of  the  flame  of  the  light.* 

•  The  difference  between  two  positions  of  the  gnomon  being  known,  to  find  the  distance  between 
the  foot  of  the  light  and  gnomon ;  and  the  elevation  of  the  light:  Ch. 

*  The  shadow  of  a  gnomon  twelve  fingers  high  is  in  one  place  fifteen  fingers.  The  gnomon  being 
removed  twenty-two  fingers  further,  its  shadow  is  eighteen.  The  distance  between  the  tips  of  the 
shadows  is  twenty-five.     The  difference  of  the  length  of  the  shadows  is  three. 

Distance  between  the  tips  of  the  shadows  25.  By  this  multiply  the  shadows  15  and  18  :  the 
products  are  375  and  450;  which,  divided  by  the  difference  of  the  shadows  3,  give  the  several 
quotients  125  and  150.  They  are  the  bases;  that  is,  the  distances  of  the  tips  of  the  shadows  from 
the  foot  of  the  light. 


100 


150  110  40 

The  grounds  or  bases  125  and  150,  multiplied  by  the  gnomon  12,  make  1500  and  1800;  which, 
divided  by  the  respective  shadows,  give  the  quotients  100  and  100 ;  or  the  elevation  of  the  light, 

alike  both  ways. 

Here  also  the  operation  of  the  rule  of  three  is  applicable  :  '  If  to  the  difference  of  the  shadows 
answers  a  side  equal  to  the  distance  between  the  tips  of  the  shadows,  what  will  answer  to  the  length 
of  the  shadow  ?'  The  answer  is  a  side,  which  is  the  distance  of  the  foot  of  the  light  to  the  tip  of 
the  shadow. 

So  to  find  the  upright,  the  proportion  is :  'If  an  upright  equal  to  the  gnomon  answer  to  a  side 
equal  to  the  shadow,  what  will  answer  to  a  side  equal  to  the  base  ?'  The  answer  gives  the  height 
of  the  flame  of  the  light. 


r 


(    319    ) 


Oi;fi 


SECTION  X. 


SUPPLEMENT. 

55.*  The  multiplicand  is  repeated  like  a  string  for  cattle,*  as  often  as  there 
are  integrant  portions^  in  the  multiplier,  and  is  severally  multiplied  by  them, 
and  the  products  are  added  together :  it  is  multiplication.  Or  the  multipli- 
cand is  repeated  as  many  times  as  there  are  component  parts  in  the  multiplier.* 


'  In  the  rule  of  multiplication  (§  3)  it  is  said  "  The  product  of  the  numerators  divided  by  the 
products  of  the  denominators  is  multiplication."  But  how  the  product  is  obtained  was  not  explained. 
On  that  account  the  author  here  adds  a  couplet  to  show  the  method  of  multiplication.  Cii. 

*  Go-sutricd;  a  rope  piqueted  at  both  ends;  with  separate  halters  made  fast  to  it  for  e9,ch.,o,\ 
or  cow.  ."Cl— ?.r  4 

'  Chanda;  portions  of  the  quantity  as  they  stand  ;  contrasted  with  hheda,  segments  or  divisions; 
being  component  parts,  which,  added  together,  make  the  whole;  or  aliquot  parts,  which,  multiplied 
together,  make  the  entire  quantity. 

♦  Example :  Multiplicand  two  hundred  and  thirty-five.  Multiplicator  two  hundred  and 
eighty-eight. 


The  Multiplicator  is  repeated  as  often  as  there  are  portions  in  the  multiplicator:  235 

235 
235 


8 
8 


Multiplied  by  the  portions  of  the  multiplier  in  their  order,  there  results  470      :  which,  added 

1880 
1880 

together  according  to  their  places,  make  6768O. 

Or  the  multiplicand  is  repeated  as  often  as  the  parts  9>  8,  151,  120;  and  multiplied  by  them 

235  9  2115       The  sum.  is  the  quantity  resulting  from  multiplication,  as  before,.  6768O. 

235  8           1880 

235  151  35485 

235  120  28200 

Or  the  parts  of  the  multiplier  are  taken  otherwise :  as  thus  9,  8,  4 ;  the  continued  multipli- 
cation of  which  is  equal  to  the  multiplier  288.  So  with  others.  And  the  multiplicand  is  succes- 
sively multiplied  by  those  divisors,  which  taken  into  each  other  equal  the  multiplicator.  Thiis 
tlie  multiplicand  235,  multiplied  by  9,  makes  2115;  which,  again,  taken  info  8,  gives  l6'920; 
and  this,  multiplied  by  4,  yields  6768O. 

This  method  by  parts  is  taught  by  Scanda-sexa  and  others.  In  like  manner  the  other  methods 
of  multiplication,  as  tat-st'ha  and  mpaia-sandhi,  taught  by  the  same  authors,  may  be  inferred  by 
the  student's  own  ingenuity.  Cb. 


320  BRAHMEGUPTA.  Chapter  XIL 

56.  If  the  multiplicator  be  too  great  or  too  small,*  the  multiplicand  is  to- 
be  multiplied  by  the  excess  or  defect  as  put ;  and  the  product  of  the  multi- 
plicand by  the  quantity  so  put  is  added  or  subtracted.* 

57-  The  quotient  of  a  dividend  by  a  divisor  increased  or  diminished  by 
an  assumed  quantity,'  is  reserved ;  and  is  multiplied  by  the  assumed  quan- 
tity, and  divided  by  the  original  divisor;  and  the  quotient  of  this  division, 
added  to,  or  subtracted  from,  the  reserved  quantity,  is  the  correct  quotient.* 

58.  The  product  of  quotient  and  divisor,'  being  divided  by  the  multi- 
plicator, is  the  multiplicand;  or  divided  by  the  multiplicand,  is  the  multi- 

Sridhaba's  rule  is  as  follows :  '  Placing  tbe  multiplicand  under  the  multiplying  quantity  in  the 
order  of  tbe  foldings  (cap&ia-sand'hi  crama),  multiply  successively,  in  the  direct  or  in  the  inverse 
order,  repeating  the  multiplier  each  time.  This  method  is  termed  capita-sand'hi*  The  next  is 
termed  tatst'ha,  because  the  multiplier  stands  still  therein  (tastnin  tisht'hati).  By  division  of  the 
form  or  separation  of  the  digits  Cfupa-st'hdna-vihMga)  that  named  from  parts  Cc'handa)  becomes 
two-fold.  These  are  four  methods  for  the  operation  of  multiplication  (pratyutpanna) .' — Gari.-tdr. 
§  15—17. 

When  the  quantity  to  be  multiplied  has  by  mistake  been  multiplied  by  a  multiplicator  too 
great  or  too  small ;  to  correct  the  error  in  such  case,  the  author  adds  a  couplet.  Cii. 

*  Example:  Multiplicand  15  ;  multiplicator  20.  This  multiplicand  has,  by  mistake,  been  mul- 
tiplied by  four  more,  viz.  by  24.  The  product  is  360.  Here  the  number  put  is  4;  and  multipli- 
cand 15  :  their  product  60.  It  is  subtracted  from  the  number  as  multiplied  :  and,  with  a  reproof 
to  the  blundering  calculator,  he  is  told  "  the  true  product  is  300." 

Or  the  multiplicand  has  been  multiplied  by  four  less  ;  viz.  l6;  and  the  product  stated  is  240. 
Here  the  product  of  the  multiplicand  and  number  put  is  60;  which  is  added,  as  the  multiplication 
was  short ;  and  the  correct  result  is  300.  Cii. 

^  When  the  dividend  has  been  divided  by  a  divisor  increased  or  diminished  by  an  assumed 
quantity  ;  to  correct  the  quotient.  Cu. 

*  Example  :     Dividend  300.     Original  divisor  20. 

The  division  being  made  with  that  increased  by  four,  viz.  24,  the  quotient  was  12  J.  This  is 
reserved,  and  is  multiplied  by  the  assumed  number  4 :  product  50  :  whence,  by  the  original  divisor, 
the  quotient  is  had  2j.     This,  added  to  the  reserved  quantity  12  J,  makes  15. 

Or  the  same  dividend  300,  being  divided  by  four  less  than  the  right  divisor,  viz.  by  J6,  the 
quotient  was  18|.  This  multiplied  by  the  assumed  number  4,  makes  75;  which  divided  by  the 
original  divisor  20,  yields  3|:  and  this  quotient,  subtracted  from  the  reserved  quantity  18  |, 
leaves  15.  Cii. 

'  Of  multiplicand,  multiplicator,  divisor  and  quotient,  to  find  any  one,  the  rest  being  knowa. 

Ciu 

*  ftom  capdta,  a  folding  door,  and  sand'hi,  junction. 


Section  X.  SUPPLEMENT.  321 

plicator :  the  product  of  multiplicand  and  multiplier,  divided  by  the  divisor, 
is  the  quotient ;  or  divided  by  the  quotient,  is  the  divisor.' 

59.  If  two  of  the  quantities,  whether  multiplicand  and  multiplicator,  or 
divisor  and  quotient,  be  wanting-,'^  [the  given  quantities  are  to  be  changed 
for  the  others,  and  arbitrary  quantities  to  be  put  in  their  places.']* 

60.  Multiply  the  multiplicand  or  the  multiplicator  by  the  denominator 
of  the  divisor  :  and  the  divisor  is  to  be  multiplied  by  the  denominator  of  the 
multiplicand,  aiid  by  that  of  the  multiplicator.' 

61.  Making  unity  denominator  of  an  integer,  let  all  the  rest  of  the  pro- 


•  Example:     Divisor  20;  multiplicand  32  ;  multiplicator  5  ;  quotients. 

First  to  find  the  multiplicand.  The  product  of  divisor  and  quotient,  20  and  8,  is  l60  :  which, 
divided  by  multiplicator  5,  gives  32. 

Next  for  the  multiplicator.  The  product  of  divisor  and  quotient  is  l60;  which,  divided  by  the 
multiplicand  32,  yields  5. 

Then  for  the  quotient.  The  product  of  the  multiplicand  and  multiplier,  32  and  5,  is  l60  : 
which,  divided  by  the  divisor  20,  affords  8. 

Lastly,  for  the  divisor.  The  product  of  the  multiplicand  and  multiplier  is  l60:  which,  divided 
by  the  quotient  8,  produces  20.  Ch. 

*  If  a  couple  of  the  quantities  be  wanting  [that  is,  unknown],  to  find  ihem.  Ch. 
'  The  text  is  deficient  in  the  manuscript ;  but  is  here  supplied  from  the  commentator's  gloss. 
♦Example:     Divisor  20;  multiplicand  32;  multipliers;  quotients. 

The  multiplicator  and  multiplicand  being  wanting ;  the  divisor  and  quotient  are  20  and  8.  These 
are  put  for  multiplicand  and  multiplicator.  Their  product  is  l60.  Hence,  putting  four  for  the 
quotient,  the  divisor  is  found  40;  or  putting  eight,  it  is  20:  and  so  on  arbitrarily.  Or  the  arbi- 
trary number  may  be  the  divisor;  whence  the  quotient  is  to  be  deduced  :  and  so  on  variously. 

Or,  the  divisor  and  quotient  being  wanting,  the  multiplicand  and  multiplicator  are  32  and  5. 
These  are  converted  into  divisor  and  quotient,  or  quotient  and  divisor.  Their  product  is  l60' 
Putting  ten,  an  assumed  quantity,  either  for  the  multiplicand  or  for  the  multiplicator;  the  other, 
namely  multiplier  or  multiplicand,  is  deduced  l6:  or,  putting  five,  the  number  deduced  is  32.  So, 
a  hundred  different  ways.  Ch. 

'  To  make  the  terms  homogeneous  in  the  rule  of  three.— Ch.  It  it  thesarae  in  effect  with  that 
before  delivered  and  expounded.  §  4:  lb. 

T  T 


822  BRAHMEGUPTA.  Chapter  XIL 

cess  be  as  above  described.'     The  divisor  and  multiplicator,  or  divisor  and 
multiplicand,''  arc  to  be  abridged  by  a  common  measure.' 

62.  The  integer,  multiplied  by  the  sexagesimal  parts  of  the  fraction  be- 
longing thereto,  and  divided  by  thirty,  is  the  square  of  the  fractional  por- 
tion* to  be  added  to  the  square  of  the  whole  degrees.'  A  s(juare  and  a  cube 
are  the  products  of  two,  and  of  three,  like  quantities  multiplied  together.* 

63.''  Twice  the  less  portion*  of  a  quantity  [added  to  the  greater']  being 
multiplied  by  the  greater  and  added  to  the  square  of  the  less,  is  the  entire 
square."     Or,  an  arbitrary  number  being  added  to,  and  subtracted  from,  the 

'  It  has  been  so  shown  by  us  in  preceding  examples. — Ch.     SeenoteoD§5. 

*  Never  the  multiplicand  and  multiplicator.  Cii. 

'  They  are  to  be  reduced  to  least  terms  by  a 'common  divisor,  if  the  case  comport  it;  to  abbre* 
Tiate  the  work. 

Example:     Divisor  20;  multiplicand  40. 

These,  being  abridged  by  the  common  measure  twenty,  become  1,2. 

So,  divisor  20;  multiplicator  4. 

Reduced  by  the  common  measure  four,  they  become  5,  I. 

*  Vicala-varga,  square  of  the  minutes;  the  multiple  of  the  fraction  to  be  added  to  the  square  of 
the  integer,  to  complete  the  square  of  the  compound  quantity.     See  §64. 

'  To  find  the  square  of  a  quantity,  that  includes  minutes  of  a  degree.  Ch. 

The  rule  may  be  stated  otherwise  [and  more  generally].  The  integer,  multiplied  by  the  nu- 
merator of  its  attendant  fraction,  which  has  a  given  deiiominator,  being  divided  by  [half  J  its  de- 
nominator, is  to  be  added  to  the  square  of  the  integer  portion. — Ibid.  This  method  gives  the 
square  grossly:  being  less  than  the  truth  by  the  product  of  the  minutes  by  minutes,  expressed  in 
sexagesimal  seconds.  lb. 

Example:     What  is  the  square  of  fifteen  degrees  and  a  half?     Statement :     13°  30'. 

The  integer  15,  multiplied  by  the  sexagesimal  parts  or  minutes,  30,  is  450:  which,  divided  by 
thirty,  gives  15,  to  be  added  to  the  square  of  the  whole  degrees,  or  225  ;   making  in  all  240. 

So  square  of  twelve  and  a  twelfth  part?     Statement:   12°  05'.     Answer:   146. 

*  Definition  of  square  and  cube. — Ch.  The  continued  multiplication  of  four  or  more  like  quan- 
tities is  termed  tadgata,  as  the  author  afterwards  notices  in  the  chapter  on  Algebra  CcuttaLdd'hyiit/aJ. 

ib. 

''  To  find  the  square  of  a  quantity.  Cii. 

*  Or  the  greater  may  be  taken ;  or  any  two  portions  of  the  proposed  quantity  may  be  employed  ; 
or  a  greater  number  of  portions,  Ch. 

9  The  text  is  obscure,  and  the  comment  deficient :  but  either  it  must  be  thus  supplied,  or  the 
sense  must  be  '  the  quantity  added  to  its  least  portion' :  or  else  the  square  of  the  greater  portion,  as 
well  as  of  the  less,  must  be  added  after  the  multiplication. 

'"  Example  :     Square  of  twenty-five. 

Here  five  is  the  less  portion,  and  twenty  the  greater.    The  less  portion  of  the  quantity  doubled 


I 


Section  X.  SUPPLEMENT.  323 

quantity,  the  product  of  the  sum  and  difference,  added  to  the  square  of  the 
assumed  number,  is  the  square  required.^ 

64 — 65.'  To  the  square  of  the  given  least  quantity  add  the  square  of  the 
fractional  portion^  of  the  other,  and  from  it  subtract  the  same:*  the  sum  and 
difference  are  divided  by  twice  the  other  number,^  and  in  the  second  place 
by  the  same  divisor  together  with  the  first  quotient  added  and  subtracted: 
the  [last  corrected]  divisor  with  the  same  quotient  [again]  added  and  sub- 
tracted, being  halved,  is  the  root*  of  the  sum  and  of  the  difference  of  squares. 
Or  the  other  number,  with  the  quotient  added  and  subtracted,  is  so.^ 

[and  added  to  the  greater]  is  30 :  which,  being  multiplied  by  the  greater,  makes  600.    The  square  . 
of  the  less  25.     Their  sum  is  625,  the  square  of  twenty-five. 

Or  the  greater  portion  [added  to  the  quantity]  is  45 :  which,  multiplied  by  the  less  is  225. 
Added  to  the  square  of  the  greater,  viz.  400,  the  sum  is  625. 

Or  one  portion  of  the  quantity  20  [doubled  and]  multiplied  by  the  second,  makes  200  :  and 
this,  added  to  the  squares  of  the  portions,  400  and  25,  gives  625. 

Or  one  portion  of  the  quantity  5,  doubled,  and  multiplied  by  the  other,  makes  200;  and  this, 
added  to  the  squares  of  the  portions,  produces  625. 

Or  let  there  be  three  portions  of  twenty-five  :  as  5,  7  and  13.  One  portion  of  the  quantity,  5, 
doubled,  is  10:  which,  multiplied  by  the  second  7,  makes  70:  and  added  to  the  squares  of  the 
portions,  viz.  25  and  49,  produces  144.  Its  root  is  12  :  with  which  and  with  thirteen  the  operation 
■  proceeds.  Ch. 

'  Example  25. 

Adding  and  subtracting  the  arbitrarily  assumed  number  five,  it  becomes  30  and  20.  The  pro- 
duct of  these  is  600 :  which,  added  to  the  square  of  the  assumed  number  5,  viz.  25,  makes  625. 

Ch. 

*  To  find  a  quantity  such  that  its  square  shall  be  equal  to  the  sum  of  the  squares,  or  to  the  dif- 
ference of  the  squares,  of  two  quantities,  of  which  the  greater  does   not  exceed  the  square  of  the 

fractional  portion,  nor  the  square  of  the  less  number.  Ch. 

^  Square  of  the  sexagesimal  minutes ;  that  is,  the  multiple  of  the  fraction.     See  §  62. 

*  The  rule  serves  for  finding  both  quatitiesat  once ;  the  additions  being  every  where  adapted  to 
bring  out  the  root  of  the  sum  of  the  squares;  and  the  subtractions,  to  give  the  root  of  the  difference 
of  the  squares. 

'  Itara,  the  other;  other  than  the  least;  that  is,  the  greater  number. 
'  Approximately. 

*  Example  for  the  sum  :  Let  the  greater  number,  termed  the  other  quantity,  together  with  its 
minutes,  be  15°  40';  and  the  least  be  14.  The  square  of  the  latter  is  196.  The  square  nf  the 
fractional  portion  is  20.  Added  they  make  2l6  ;  which,  divided  by  twice  the  other  quantity  15,  viz. 
30,  gives  in  the  first  place  6 ;  and  this,  added  to  the  divisor  30,  makes  36;  by  which,  in  the  second 
place,  the  correct  quotient  comes  out  6.  This  again  is  added  to  the  correct  divisor ;  and  the  sum 
is  42:  which  halved  yields  21,  the  number  sought.     For  the  square  of  the  number  thus  found  is 

T  T  2 


324  BRAHMEGUPTA.  Chapter  XII. 

ji,  66.  This  is  a  portion  only  of  the  subject.*  The  rest  will  be  delivered 
under  the  construction  of  sines/  and  under  the  pulverizer.^  [End  of]  chapter 
twelfth  [comprising]  sixty-six  couplets  on  addition,  &c. 

'441  :  from  which  subtracting  the  square  of  the  least  number  1 96,  the  remainder  is  245,  the  square* 
of  the  greater  number  15°  40'.     Subtracting  this  square,  the  remainder  is  nought. 

Or,  adding  the  quotient  6  to  the  other  quantity  15,  the  sum  21  is  a  number  equal  to  the  square- 
root  of  the  sum  of  the  squares. 

Example  of  the  difference:  The  other  quantity  or  greater  number  is  12°  SO'.  The  least  10. 
The  square  of  this,  100.  The  square  of  the  fractional  portion  is  20;  which,  subtracted,  leaves  80. 
This,  divided  by  the  other  quantity  doubled,  24,  yields  in  the  first  place 4;  which,  subtracted  from 
the  [first]  divisor,  leaves  20.  The  corrected  quotient  4,  subtracted  from  the  corrected  divisor  20, 
affords  the  remainder  16,  the  half  of  which  8  is  equal  to  the  diflerence  of  squares. 

Or,  subtracting  the  quotient  4  from  the  other  quantity  12,  the  residue  8  is  a  number  equal  to 
the  square  root  of  the  difference  of  squares.  Thus,  its  square  is  64;  and  so  much  is  the  difference 
between  the  squares  of  the  greater  and  least  quantities  l64t  and  100.  Cii. 

'  A  portion  only  has  been  here  shewn;^  and  a  portion  only  has  been  by  us  expounded.  Else  a 
hundred  volumes  would  be  requisite  under  a  single  head.  But  we  have  undertaken  to  interpret 
the  whole  astronomical  course  (sidd'hanta).     Wherefore  prolixity  is  to  be  shunned.  Ch. 

•  Jyotpatti  (jyd-utpatti)  derivation  of  [semi-]chords:  taught  in  the  chapter  on  Spherics,  and  to 
be  there  expounded  (C.  21,  §  15—21).  Ch. 

^  In  the  Chapter  on  the  Pulveri2er  (cuttac&'d'hy&ya)  the  author  will  treat  the  undsrmentioned 
topics  with  other  heads  of  computation:  viz.  Investigation  of  the  pulvesizer  (cMttaca).  Algorithm 
of  symbols  or  colours  ('rarnaj ;  of  affirmative  and  negative  quantities  d'lianarna) ;  of  surd  roofs 
(carani).  Concurrence  (sancramana).  Dissimilar  operation  (lishama-carmanj.l  Equation  of 
the  unknown  (avyacta-s&mya) .  Equation  of  several  unknown  letters  or  colours  (varnasdmya) . 
Elimination  of  the  middle  term  (mad'hyamii'haranaj.  Equation  involving  products  of  unknown 
quantities  (bhdvica).     Affected  square  (varga-pracriti),  &cc.  Cij. 

•  Nearly  so.     The  exact  square  is  34o|;  or  in  sexagesimals  245°  26'  40".. 
t  The  exact  square  is  164^ ;  in  sexagesimals  164°  41'  40".. 

i  See  Ch.  18,  $25  and  L«,  55—57. 


CUTTACAD  HYAYA,    ON    ALGEBRAj 

THE  EIGHTEENTH  CHAPTER  OF  THE 

BRAHME-SPHUTA-SIDD'HANTA, 
BY  BRAHMEGUPTA: 

WITH  NOTES  SELECTED  FROM  THE  COMMENTARY. 

CHAPTER  XVIII. 

ALGEBRA. 


SECTION  I. 


1.  Since  questions  can  scarcely  be  solved  without  the  pulverizer,*  there 
fore  I  will  propound  the  investigation  of  it  together  with  problems. 

2.  By  the  pulverizer,  cipher;  negative  and  affirmative  quantities,  un- 
known quantity,  elimination  of  the  middle  term,  colours  [or  symbols]  and 
factum,  well  understood,  a  man  becomes  a  teacher  among  the  learned,  and 
by  the  affected  square. 

3 — 6.  Rule  for  investigation  of  the  pulverizer:  The  divisor^  which  yields 
the  greatest  remainder,  is  divided  by  that  which  yields  the  least:  the  residue 
is  reciprocally  divided ;  and  the  quotients  are  severally  set  down  one  under 
the  other.  The  residue  [of  the  reciprocal  division]  is  multiplied  by  an 
assumed  number  such,  that  the  product  having  added  to  it  the  difference  of 
the  remainders  may  be  exactly  divisible  [by  the  residue's  divisor].     That 

'  CiUtdcura,  cut  to,  cuttaca,  pulverizer.    See  Lil.  §^248  and  Vij-gad..^  53. 


326  BRAUMEGUPTA.  Chapter  XVIII. 


s 


multiplier  is  to  be  set  down  [underneath]  and  the  quotient  last.  The  penul- 
timate is  taken  into  the  term  next  above  it;  and  the  product,  added  to  the 
ultimate  term,  is  the  agranta}  This  is  divided  by  the  divisor  yielding  least 
remainder;  and  the  residue,  multiplied  by  the  divisor  yielding  greatest 
remainder  and  added  to  the  greater  remainder,  is  a  remainder  of  [division  by] 
the  product  of  the  divisors.  A  twofold  ^wo-a  is  a  product  of  divisors:*  and 
the  elapsed  portion  of  the  yuga  is  the  remainder  of  the  two.  Thus  may  be 
found  the  lapsed  part  of  a  yuga  of  three  or  more  planets  by  the  methotl  of 
the  pulverizer. 

7.  Question  1.  He,  who  'finds  the  cycle  (yuga)  and  so  forth,  for  two, 
three,  four  or  more  planets,  from  the  respective  elapsed  cycles  of  the  several 
planets  given,  knows  the  method  of  the  pulverizer. 

Here,  for  facility's  sake,  the  revolutions,  &c.  ofthesim  and  the  rest  are  put, 
as  follows:  the  sun  30;  the  moon  400;  Mars  16;  Mercury  130;  Jupiter  3; 
Venus  50;  Saturn  1 ;  moon's  apogee  4;  moon's  node  2;  revolutions  of  stars 
10990;  solar  months  360;  lunar  months  370;  more  months  (lunar  than  solar) 
10;  solar  days  10800;  lunar  days  1 1100;  fewer  days  (terrestrial  than  lunar) 
140;  terrestrial  days  IO96O. 

The  days  of  the  planetary  cycles  of  the  sun  and  the  rest  are  [sun]  IO96; 
moon  137;  Mars  685;  Mercury  and  Venus  IO96;  Jupiter  IO96O;  Saturn 
IO96O;  apogee  2740;  node5480.' 

Example  (a  popular  one  is  here  proposed):  What  number,  divided  by  six, 
has  a  remnant  of  five;  and  divided  by  five,  a  residue  of  four;  and  by  four,  a 
remainder  of  three;  and  by  three,  one  of  two? 

Statement:    5     4     3     2         [Answer  59.]* 
6     5     4     3 

'  Agr&nta.    The  proper  import  of  the  term,  as  it  is  here  used,  is  unexplained. 

*  This  is  introduced  in  contemplation  of  instances  relative  to  planets:  and  so  is  what  follows. 

Com. 

OD^  5  K-f  "h  J'sJ's 

'  Periodical  revolu-  7  Apogee.      Noda 

tions  in  least  terms:       j  3  5         113  35  1  1  1 

da°s'In°^'st  terms •"*' [       ^^^^       "^     ^^^     ^^^^     ^°^^"     ^°^^     ^^^^^       ^'^'^       ^^^^ 
*  The  divisor  vrhich  yields  the  greater  remainder,  namely  6,  being  divided  by  that  which  yields 


Section  I.  PULVERIZER.  327 

8.     Rule  for  deducing  elapsed  time  from  residue  of  revolutions,  &c.  §  7- 
Let  residue  of  revolutions  or  the  like,  divided  by  the  divisor,  be  a  remainder; 

the  less,  viz.  5,  the  residue  is  ^.  Then,  reciprocal  division  taking  place,  the  quantity  beneath  is  in 
the  first  instance  to  be  divided  by  that  which  stands  above  it :  and  thus  the  quotient  is  5  and  the 
residue  f .  This  is  multiplied  by  a  quantity  so  assumed  as  that  the  product  having  the  difference 
of  the  remainders  (namely  1)  added  to  it,  may  be  exactly  divisible  by  the  [residue's]  own  divisor  1. 
The  quotient  being  solitary,  the  difference  of  remainders  is  in  this  case  to  be  subtracted  [§  13]. 
The  number  so  assumed  is  put  1.  By  that  the  residue  0  being  multiplied,  isO;  which,  having  sub- 
tracted from  it  the  difference  of  remainders  I,  makes  1  ;  and  this  divided  by  the  [residue's]  own 
divisor,  namely  1,  yields  for  quotient  negative  unity.  Statement  of  the  first  quotient  and  the  mul- 
tiplier and  present  quotient  5       By  the  penultimate  1  multiplying  the  term  next  above  it  5,  the 

1 

i 

product  is  5  ;  which  added  to  the  ultimate  1,  makes  4.     The  agrdnta  thus  comes  out  4.     Divided 

by  the  divisor  yielding  least  remainder,  viz.  5,  the  residue  is  4:  which,  multiplied  by  the  divisor 

yielding  greatest  remainder  6,  produces  24;  and  this,  added  to  the  greater  remainders,  affords  the 

remainder,  29,  of  the  product  of  the  divisors :  that  is  to  say,  so  much,  namely  29,  is  the  remainder 

of  the  number  in  question  (which  divided  by  six  has  a  remnant  of  five,  and  divided  by  five  a  residue 

of  four,)  divided  by  a  divisor  equal  to  the  product  of  the  divisors,  viz.  30. 

Again,  statement  of  the  foregoing  result  with  the  third  term     29     3     Here  the  divisor  yielding 

30     4 

the  greater  remainder,  30,  being  divided  by  that  which  yields  the  less,  viz.  4,  the  residue  is  f . 
Then  by  reciprocal  division  the  quotient  is  2  and  the  residue  f .  This,  multiplied  by  an  assumed 
multiplier  seven,  produces  0;  which,  having  subtracted  the  difference  of  remainders  26,  makes  26"; 
and  divided  by  the  [residue's]  own  divisor  2,  the  quotient  is  13.  Statement  of  the  former  quotient, 
the  multiplier  and  the  [present]  quotient     2     Proceeding  by  the  rule  (the  penult  taken  into  the 

7 
13 
term  next  above  it,  &c.  §  5),  the  agrunta  comes  out  1.     This  being  divided  by  the  divisor  yielding 
least  remainder,  the  residue  is  1 ;  which,  multiplied  by  the  divisor  yielding  greatest  remainder  30, 
is  30,  and  added  to  the  greater  remainder  29,  makes  59,  the  remainder  answering  to  the  product 
of  the  divisors,  viz.  60. 

Wherever  abridgment  of  the  divisors  [by  a  common  measure]  is  practicable,  the  product  of  divi- 
sors must  be  understood  as  equal  to  the  product  of  the  divisor  yielding  greatest  remainder  and 
quotient  of  the  divisor  yielding  least,  abridged  \i.  e.  divided]  by  the  common  measure  :  and  when 
one  divisor  is  exactly  divisible  by  the  other,  the  greater  remainder  is  the  remainder  required,  and 
the  divisor  yielding  greatest  remainder  is  taken  for  product  of  divisors.  This  is  to  be  elucidated  by 
the  intelligent  mathematician,  by  assumption  of  several  colours  (or  symbols). 

Again,  this  number  59,  of  itself  answers  to  the  condition  that  divided  by  three,  it  shall  have  a 
residue  of  two. 

Example  of  Question  1.  Elapsed  part  of  the  cycles  of  the  sun,  &c.  together  with  the  divisors, 
as  follows : 


328  BR AHME GUPTA.  Chapter  XVIII. 

Sun.         Moon.      Mars.     Mercury.      Jupiter.       Venus.      Saturn.    Apogee  B .    Node  D . 
1000  41  315  1000  1000  1000  1000  1000  1000 

1096  137  685  1096  10960  1096  10960  2740  5480 

Here  the  divisor  yielding  greatest  remainder,  IO96,  is  exactly  measured  by  that  which  )nelds  least 
137  :  wherefore  the  remainder  is  the  same,  and  the  same  [divisor]  is  taken  for  the  product  of  divi- 
sors; 1000 
1096 

The  sequel  of  the  rule  "  A  two-fold  yuga  is  a  product  of  divisors"  (§  6)  is  next  expounded:  so 
many  days,  as  suffice  for  the  commencement  of  exceeding  months  and  deficient  days,  and  the  ter- 
mination of  the  sun  and  moon's  revolutions,  to  take  place  again  on  the  first  of  Chaitra,  light  fortnight, 
at  sunrise  at  Lancd,  are  days  of  a  two-fold  cycle ;  and  this  is  what  is  termed  a  two-fold  yuga.  The 
remainder,  as  found,  is  the  elapsed  portion  of  a  two-fold  yuga.  In  like  manner  are  to  be  understood 
three-fold  cycles  and  so  ibrth. 

Again,  statement  of  the  same  with  the  residue  and  divisor  of  Mars  :    1000    315     Here  the  divi- 

1096    685 

sor  yielding  greatest  remainder,  IO96,  is  divided  by  the  divisor  yielding  least,  namely  685  ;  and  the 

residue  is  |^.     Then  the  quotients  resulting  from  reciprocal  division  are  put  one  under  the  other 

1     and  the  residue  is  -j^;  which,  multiplied  by  an  arbitrary  multiplier  three,*  makes  0;  and  this 

1 

2 

lessened  by  the  subtraction  of  the  difference  of  remainders,  viz.  685,  and  divided  by  its  own  divisor 

137,  yields  the  quotient  5.    The  multiplier  and  quotient,  thus  found,  are  put  below  the  former 

quotients,  one  under  the  other :  and  that  being  done,  a  series  is  obtained  1      Proceeding  as  before, 

1 
3 
3 

5 

the  agr&nta  comes  out  5.  This  being  divided  by  the  divisor  yielding  least  remainder,  685,  the 
residue  which  results  is  5  ;  which,  multiplied  by  the  divisor  yielding  greatest  remainder  and  having 
the  greater  remainder  added,  brings  out  the  remainder  6480.  It  is  the  elapsed  portion  of  a  three- 
fold yvga.  The  divisor  yielding  greatest  remainder  IO96,  being  multiplied  by  5  the  quotient  of  the 
divisor  yielding  least  remainder  abridged  by  the  common  measure  137,  produces  the  three-fold 
yuga,  5480.  But  it  is  not  fit,  that  the  elapsed  portion  of  a  cycle  should  exceed  the  cycle  :  it  is 
therefore  abridged  by  ihnyuga;  and  the  residue  must  be  considered  as  the  elapsed  portion  of  a 

yuga.     This  being  done,  there  results  1000     Next  statement  of  the  same  with  the  elapsed  portion 

5480 

of  Mercury's  ^^Kga  .•  1000     1000     Here  either  divisor  at  choice  may  be  taken  as  the  one  yieldi.ig 
5480     1096 

greatest  remainder.  Put  5480.  The  elapsed  portion  of  the  four-fold  yuga  is  1000.  In  like  man- 
ner, by  the  operation  of  the  pulverizer  with  the  respective  elapsed  portions  of  yugas  of  Jupiter,  ■» 
Venus  and  Saturn,  the  elapsed  portions  of  cycles  come  out  [Jupiter]  1000,  Venus  1000  and  Sa- 
turn 1000;  and  the  measure  of  the  cycles  as  follows:  viz.  five-fold  yuga  IO96O;  six-fold  yuga 
IO96O;  seven-fold  yi/g:a  IO96O.  In  like  manner  the  process  of  the  pulverizer  being  observed  with 
the  elapsed  periods  of  the  yugas  of  the  moon's  apogee  and  node,  the  elapsed  portion  of  the  entire 
cycle  for  all  the  planets  comes  out  1000,  and  the  value  of  such  entire  yuga  IO960. 

*  Sic :  sed  qncre. 


Section  1.  PULVERIZER.  329 

as  also  cipher  divided  by  residue  arising  for  one  day.*  The  remainder  de- 
duced from  these,  being  divided  by  residue  of  revohitions  or  the  hke  as  arising 
for  one  day,'  is  the  number  of  [elapsed]  days. 

9.  Question  2.  He,  who  deduces  the  number  of  [elapsed]  days  from  the 
residue  of  revolutions,  signs,  degrees,  minutes,  or  seconds  declared  at  choice, 
is  acquainted  with  the  method  of  the  pulverizer. 

Example:  When  the  remainder  of  solar  revolutions  is  eight  thousand  and 
eighty,  tell  the  elapsed  portion  of  the  cafpas,  if  thou  have  skill  in  the  pulve- 
rizer. 

Statement:    Residue  of  revolutions  8080.*     [Answer:  1000.] 

The  foregoing  rule  (§  3)  for  dividing  the  divisor  which  yields  the  greater  remainder  by  that  which 
yields  the  less,  is  unrestrictive  ;  and  the  process  may  therefore  be  conducted  likewise  by  dividing  the 
divisor  which  yields  the  less  remainder  by  that  which  yields  the  greater. 

Example:  What  number,  divided  by  seventy-three,  has  a  remnant  of  eight ;  and  divided  by  thir- 
teen, a  remainder  of  three? 

Statement:     8         3     Dividing  the  divisor  which  yields  the  less  remainder  by  that  which  affords 
73       13 

the  greater,  and  the  residue  being  reciprocally  divided,  the  quotients  are     5     The  residue  J. 

1 
1 
1 
1 

Assumed  multiplier  1.  Difference  of  remainders  5.  Here,  since  the  process  was  inverted,  the 
difference  of  remainders  is  made  negative,  5;  and,  as  the  quotients  are  uneven,  it  again  becomes 
affirmative,  5 :  consequently  it  is  additive.  Proceeding  as  before,  the  agrdnta  comes  out  TQ.  This 
is  divided  by  the  divisor  yielding  the  greater  remainder;  and  the  residue  6,  multiplied  by  the  divi- 
sor yielding  the  less  remainder,  13,  makes  78;  and,  added  to  the  less  remainder  3,  brings  out  the 
quantity  sought  81. 

'  By  the  daily  increment  of  it. 

*  This  divided  by  terrestrial  days,  and  both  solar  revolutions  and  terrestrial  days  abridged  by  the 
common  measure  10,  must  be  put  for  a  remainder,  -f^fig.  Then  cipher  divided  by  residue  of  solar 
revolutions  arising  on  one  day,  namely  3,  is  put  for  the  [other]  remainder,  f.  Proceeding  by  the 
rule  (§  3)  the  series  is      3*     Whence,  by  the  subsequent  rule  (§  5),  the  remainder  comes  out  3000; 

270 

808 

and  this,  divided  by  residue  of  revolutions  arising  for  one  day,  3,  gives  the  number  of  [elapsed] 

days  1000.     In  like  manner,  from  the  residue  of  signs  and  so  forth,  the  number  of  [elapsed  days]  is 

to  be  found. 

•  Sic  MS. 


3S0  BRAHMEGUPTA.  Chapter  XVIII. 

10.  Rule  for  finding  elapsed  time  from  given  residue  for  hours:  §  8. 
From  the  result,  which  is  derived  from  residues  of  revolutions  or  the  like  for 
one  day,  and  for  the  proposed  hours  or  minutes,  both  reduced  to  like  deno- 
minators,' the  number  of  [elapsed]  days  and  so  forth  may  be  deduced. 

Example :  To  what  number  of  [elapsed]  days  does  that  amount  of  hours 
correspond,  for  which  the  residue  of  lunar  revolutions  arising  is  four  thousand 
one  hundred  and  five? 

Statement:  Residueofrevolutions,  with  divisor, -*-i-2-f.  Residue  as  arising 
for  a  single  day,  with  divisor,  ^-fy.  The  divisor  is  multiplied  by  sixty;  and 
thus  both  terms  have  like  denominators.  Cipher  divided  by  the  residue  of 
revolutions  for  one  day  must  be  put  as  a  remainder,  f.  Thus  the  statement 
is  *^°g  f.  Statement  of  the  same  abridged  by  five,  -^^jV  f .  Proceeding 
as  before,  the  remainder  is  821.  This,  divided  by  the  remainder  [of  revolu- 
tions] for  an  hour,  namely  1,  gives  the  elapsed  time  in  hours,  821;  which, 
divided  by  sixty,  yields  quotient,  days  13,  hours  41.  Or,  with  an  additive  in 
hours  equal  to  the  same  divisor  1(544,  the  elapsed  time  in  hours  is  2465  or 
4109. 

1 1—13.  Rules  for  a  constant  pulverizer:  §  9 — 1 1.*  The  multiplier  and 
divisor  being  mutually  divided,  these  quantities  divided  by  the  residue  are 
[in  least  terms,  being]  irreducible  by  any  [further  common]  divisor.'  The 
quotients  of  these  reciprocally  divided  are  to  be  set  down  one  under  the  other. 
Tlie  residue  is  multiplied  by  a  multiplier  chosen  such  that  the  product  less 
one*  may  be  exactly  divisible.     That  multiplier  is  to  be  set  down;  and  the 

•  That  is,  when  the  proposed  residue  of  revolutions  is  calculated  for  elapsed  time  reduced  to 
houis  and  minutes,  then  the  residue  of  revolutions,  &c.  for  one  day  must  have  its  divisor  multi- 
plied by  sixty  or  by  three  thousand  six  hundred;  and  thus  the  denominators  are  alike.         Com. 

•  St'hira-cuttaca  ;  drfftha-cuttaca;  the  steady  residue,  by  which  the  given  remnant  of  revolu- 
tions or  the  like  is  to  be  multiplied;  and  the  product  being  divided  by  the  divisor,  the  quotient  is 
elapsed  time. — Com.  From  sfhira,  steady;  and  drM'ha,  firm.  DriiCha,  which  the  commentator 
makes  equivalent  to  st'hira  in  the  compound  terra  designating  this  multiplier,  is  by  Biia'scara  em- 
ployed in  the  sense  for  which  Brahmegupta  employs  nich'heda,  &c.     See  Lil.  §  248. 

*  NicA'hida,  nirapavarta ;  having  no  divisor;  no  further  common  measure:  reduced  to  least 
terms.     See  LU.  §  24.8. 

*  It  is  so,  if  the  quotients  be  even :  but,  if  they  be  odd,  one  must  be  added  instead  of  subtracted. 
Com.     See  §  13. 


Section  I.  PULVERIZER.  331 

quotient  at  the  end:  from  which  the  agranta,  being  found  by  multiplying 
the  next  superior  term  by  the  penultimate  and  adihng  the  ultimate  to  the 
product,  is  divided  by  the  divisor  in  least  terms.  The  residue  of  this  division 
is  the  constant  pulverizer.* 

14.  Question  3.  To  deduce  the  number  of  da3's  from  the  residue  of  re- 
volutions, &c.  of  the  sun,  and  the  rest;  tell  a  constant  pulverizer,  thou  skilful 
mathematician  who  hast  traveised  the  ocean  of  the  pulverizer. 

Here  to  find  a  constant  pulverizer  from  a  residue  of  revolutions  of  the  sun, 
the  statement  of  revolutions  and  terrestiial  days  is        30     These  are  multi- 

logdo 

plier  and  divisor.     Statement  of  them  abridged  bv  ten:         3     The  quotient 

1096 
of  these  mutually  divided  is  365,  and  remainder  ■^.  Multiplied  by  an  assumed 
multiplier,  namely  2,  the  product  is  2;  to  which  one  is  added,  since  the  quo- 
tient is  an  odd  number  [§  13];  and  the  sum  divided  by  the  divisor  gives  the 
quotient  1 ;  and  the  multiplier  and  quotient  being  set  under  the  former  quo- 
tient, the  series  is  365     Proceeding  by  the  rule  (§5)  the  agranta  is  deduced 

2 

1 

73 1 :  from  which  divided  by  the  divisor  in  least  terms,  the  residue  or  constant 
pulverizer  is  731  for  a  residue  of  revolutions. 

'  When  a  constant  pulverizer  is  sought,  to  deduce  elapsed  time  from  remainder  of  revolutions, 
then  revolutions  of  the  planet  are  multiplier,  and  terrestrial  days  divisor.  When  it  is  so  to  deduce 
the  time  from  remainder  of  signs;  twelve  times  the  revolutions  are  multiplier,  and  terrestrial  days 
divisor.  When  it  is  investigated  to  conclude  the  time  from  residue  of  degrees;  three  hundred  and 
sixty  times  the  revolutions  are  multiplier,  and  terrestrial  days  divisor.  When  it  is  so  to  conclude 
the  time  from  residue  of  minutes,  &c.  sixty  times  the  foregoing  multiple  of  revolutions  are  multi- 
plier, and  terrestrial  days  everywhere  divisor.  The  multiplier  and  divisor,  which  are  thus  put  to 
find  the  constant  pulverizer,  must  be  reciprocally  divided,  and  by  the  residue  remaining  the  same 
multiplier  and  divisor  being  divided  are  irreducible  [or  in  least  terms];  that  is,  they  can  be  no  fur- 
ther abridged  by  a  common  measure.  The  same  irreducible  multiplier  and  divisor  are  again  mu- 
tually divided  until  the  residue  in  the  dividend  be  unity.  Set  down  the  quotients  one  under  the 
other.  Multiply  the  residual  unity  by  a  multiplier  taken  such  that  the  product  less  one,  (or,  if  the 
quotients  be  odd,  having  one  added)  may  be  exactly  divisible  by  the  residue's  own  divisor.  The 
multiplier  and  the  quotient  of  this  operation  are  to  be  set  down,  in  order,  under  the  former  quo- 
tients. Then  the  agranta  is  to  be  computed  from  the  bottom  :  by  taking  the  penultimate  into  the 
next  superior  term  and  adding  the  ultimate.  The  agr&nta  so  found  is  divided  by  the  irreducible 
divisor,  and  the  residue  is  the  constant  pulverizer.  Com. 

U  U  2 


J5<2  BRAHMEGUPTA.  Chapter  XVIII. 

Then  the  nuiltipher  for  a  residue  of  signs  is  36;  and  the  ahridged  divisor 
1096.     From  which,  as  before,  the  constant  pulverizer  conies  out  61. 

Multipher  for  a  residue  of  degrees  1080.  Divisor  IO96.  From  these,  as 
before,  the  constant  pulverizer  is  found  68. 

For  residue  of  minutes,  pulverizer  129-  For  residue  of  seconds,  pulve- 
rizer 9- 

In  like  manner,  the  constant  pulverizer  for  the  moon  and  the  rest  must  be 
understood,  as  that  for  the  sun. 

15.  Rule  for  finding  elapsed  time  by  constant  pulverizers:  §  12.  The 
given  residue  of  revolutions,  or  the  like,  being  multiplied  by  its  pulverizer 
and  divided  by  its  divisor,  the  residue  which  arises  is  the  number  of  [past] 
days;  there  being  added  a  multiple  of  the  divisor  by  elapsed  [periods]  in  least 
terms.* 

Example:  Thou  who  hast  traversed  the  ocean  of  the  pulverizer!  tell  the 
number  of  elapsed  days,  when  the  remainder  of  degrees  is  four  thousand  and 
four  hundred. 

Statement:  This  remainder  of  degrees  4400,  being  abridged  by  the  com- 
mon divisor  80,  as  before  in  the  investigation  of  the  constant  pulverizer,  is 
reduced  to  55:  which,  multiplietl  by  the  constant  pulverizer  68,  becomes 
3740.  From  this  divided  by  the  divisor  reduced  to  least  terms  137,  the  resi- 
due which  is  deduced  is  the  number  of  [elapsed]  days  41.  To  find  the 
elapsed  time  intended  by  the  question,  this  must  have  added  to  it  a  multiple 
of  the  divisor  by  the  periods  gone  by.  In  this  case  they  are  [supposed]  seven, 
and  the  divisor  multiplied  by  that,  959,  being  added  to  the  number  as  above 
found  41,  the  number  of  [elapsed]  days  comes  out  1000. 

16.  Rule  special:  §  13.  So  when  the  quotients  are  even.  But  if  they  be 
odd,  what  is  propounded  as  negative,  becomes  affirmative;  or  as  positive,  be- 


'  Gata-nirapavarta  :  the  quotient,  which  is  obtained  when  the  elapsed  time  from  the  beginning  of 
the  yvga  is  divided  by  the  divisor  reduced  to  least  terms,  is  thus  denominated.  The  divisor,  multi- 
plied by  that,  being  added  to  the  elapsed  time  found  by  the  rule,  the  sum  is  the  elapsed  portion  of 
the  1/uga.  Com. 


Section  I.  PULVERIZER.  333 

comes  negative  :^  and  the  signs,  negative  or  affirmative,  of  multiplicand  and 
additive,  must  be  revcrsed." 

17-  Rule  of  inverse  operation :  <§  14.  Multiplier  must  be  made  divisor; 
and  divisor,  multiplier;  positive,  negative;  and  negative,  positive:  root  [is  to 
be  put]  for  square;  and  square,  for  root:  and  first  as  converse  for  last. 

18.  Question  4.  The  residue  of  degrees  of  the  sun  less  three,  being 
divided  by  seven,  and  the  square-root  of  the  quotient  extracted,  and  the  root 
less  eight  being  multiplied  by  nine,  and  to  the  product  one  being  added,  the 
amount  is  a  hundred.     When  does  this  take  place  on  a  Wednesday? 

Statement:  3— Div.  7— Root— 8— Mult.  9— Add.  1— Giv.  100.  The  af- 
firmative unity  being  made  negative,  when  applied  to  a  hundred,  the  result 
is  99.  Nine,  which  was  multiplier,  becomes  divisor.  Dividing  by  that,  the 
quotient  is  11.  Negative  eight  becomes  affirmative :  whence  19.  The  ex- 
traction of  the  root  is  converted  into  the  raising  of  the  square  361.  The 
.divisor  seven  becomes  multiplier.  Product  2527-  The  negative  three  be- 
ycomes  affirmative,  and  is  added,  2530.  This  is  residue  of  degrees;  from 
which,  the  number  of  [elapsed]  days  is  to  be  sought;  until,  with  addition  of 
the  divisor,  it  come  to  Wednesday. 

19.  Question  5.  He,  who  tells  when  a  given  residue  of  revolutions  of 
the  sun  occurs  on  a  Monday,  or  on  a  Thursday,  or  on  a  Wednesday,  has 
knowledge  of  the  pulverizer. 

20.  Question  6.  A  person,  who  can  say  when  a  residue  of  degrees  or  of 
seconds,  which  occurs  on  a  Wednesday,  will  do  so  on  a  Monday,  is  conver- 
sant with  the  pulverizer. 

2 1 .  Question  7.     One,  who  tells  when  given  positions  of  the  planets, 


■  See  preceding  instances  of  the  application  of  this  first  part  of  the  rule,  under  Example  1st,  or 
under  Problem  3  and  Rule  10. 

^  If  the  multiplicand  were  negative,  it  must  be  made  positive;  and  the  additive  must  be  made 
negative:  and  then  the  pulverizer  is  to  be  sought.  Com. 


334  BRAKMEGUPTA.  Chapter  XVIII. 

which  occur  on  certain  lunar  days,  or  on  days  of  other  denomination  of  mea- 
sure,' will  recur  on  a  given  day  of  the  week,  is  versed  in  the  pulverizer. 

22.  Rule  15:  The  number  of  [elapsed]  days,  deduced  from  the  given  re- 
sidue of  revolutions  or  the  like  by  means  of  the  pulverizer,  receives  an  addi- 
tion of  days  of  a  period  in  least  terms,  repeatedly,  until  the  intended  day  of 
the  week  be  reached. 

23.  Question  8.  He,  who  tells  the  number  of  [elapsed]  days,  seeing  the 
degrees,  &c.  of  a  given  [planet's]  mean  [place],  or  does  so  from  a  conjunction 
of  two  or  more  planets,  or  from  their  difference,  is  conversant  with  the  pul- 
veiizer. 

24 — 25.  Rule  1 6 — 17:  The  divisor  in  least  terms,  being  multiplied  by 
the  minutes,  &c.  in  the  [given]  signs,  &c.  and  divided  by  the  minutes  in  a 
revolution,  the  quotient  is  the  residue  of  revolutions:  whence  the  number  of 
[elapsed]  days  [may  be  deduced].  In  like  manner  residues  of  signs,  degrees, 
minutes  and  seconds,  are  found,  and  the  number  of  [elapsed]  days  as  before. 
Putting  arbitrary  numbers  in  places  deficient,  proceed  with  the  rest  of  the 
process  as  directed.* 

Example:  Seeing  past  signs,  degrees  and  minutes  of  Jupiter,  nought, 
twenty -two  and  thirty,  a  person,  who  tells  the  number  of  [elapsed]  days  at 
that  instant,  is  one  conversant  with  the  pulverizer. 

Statement:     0     Its  minutes  1350,  multiplied  by  Jupiter's  divisor  in  least 
22 
30 

terms  IO96O,  and  divided  by  the  minutes  of  a  circle;  the  quotient  is  the 

'  As  solar,  or  siderial,  &c. — Com. 

'^  The  place  of  a  planet  in  signs,  &c.  being  refhiced  to  degrees,  minutes,  and  so  forth,  the  num- 
ber of  minutes  is  multiplied  by  the  particular  divisor  in  least  terms,  and  divided  by  the  minutes  of 
a  circle ;  and  the  quotient  is  the  remainder  of  revolutions.  If  it  be  the  number  of  degrees,  &c.  the 
quotient  is  then  remainder  of  signs.  If  it  be  so  of  minutes,  &c.  the  quotient  is  remainder  of  de- 
grees. From  these  residues,  the  number  of  [elapsed]  days  is  found  as  before.  There  is  this 
difference:  when  (degrees  being  divided  by  the  minutes  of  a  circle)  any  residue  arises,  it  is  to  be 
rejected  :  the  quotient  is  taken. 


1 


Section  I.  PULVERIZER.  335 

residue  of  revolutions  685.     Whence  the  number  of  [elapsed]  days,  as  before, 
comes  ou :  7535. 

Example:  When  Jupiter  and  the  lunar  node  are  conjunct  having  passed 
signs,  degrees  and  minutes,  three,  twenty-two  and  thirty;  tell  me  the  num- 
ber of  [elapsed]  days. 

Conjunction  of  Jupiter  and  the  node      3     Reduced  to  minutes,  multi- 

2,2 
30 

plied  by  terrestrial  days,  and  divided  by  minutes  of  a  circle,  the  quotient  is 

the  sum  of  residues  of  revolutions  3425.     Whence,  as  before,  the  number  of 

[elapsed]  days  is  deduced  685. 

Example :  Tell  me  the  number  of  days  elapsed  on  a  day  when  the  body 
of  the  sun,  less  the  conjunction  of  Jupiter  and  the  lunar  node,  is  just  so  much. 

Statement:  3  £2  30.  Hence,  as  before,  the  residue  of  degrees  of  the 
sun,  less  the  residue  of  revolutions  of  Jupiter  and  the  lunar  node,  is  found 
3425.  Whence  the  number  of  [elapsed]  days,  by  the  rule  §  7,  comes  out 
137- 

Example :'  Signs  and  degrees  of  Jupiter  have  been  effaced  by  the  boy 
with  his  finger.  Thirty  minutes  are  seen  :  from  which  tell  me,  astrologer, 
the  signs,  degrees,  and  number  of  days,  if  thou  have  practice  of  the  pul- 
verizer. 

Statement :     0     Here  put  unity  in  the  place  of  signs ;  and  in  that  of  de- 
0 
30 
grees,  ten.     See:     1     Hence  the  residue  of  revolutions  is  deduced  1233: 
10 
10 

from  which  the  number  of  days,  as  before,  comes  out  411. 

26.  Question  Q.  From  the  residue  of  signs,  degrees,  minutes  or  seconds, 
told,  or  if  lost  assumed,  he  who  finds  the  superior  and  intermediate  terms,  is 
a  person  conversant  with  the  pulverizer. 

'  A  stanza  and  a  half. 


336  BRAHMEGUPTA.  Chapter  XVIII. 

27.  Rule  18.  Tlie  multiplier,  by  which  the  divisor  being  multiplied, 
and  having  the  residue  added  to  the  product,  becomes  exactly  divisible,  is 
the  [portion  of  orbit]  past.  The  quotient  is  the  residue.  In  like  manner 
from  the  residue,  [the  place  of  J  the  planet  and  the  number  of  [elapsed]  days 
are  [deduced]. 

Example  :  From  the  residue  of  seconds  of  the  moon  being  eight  hundred, 
tell  the  [place  of  the]  moon  and  number  of  [elapsed]  days,  my  friend  who 
hast  traversed  the  ocean  of  the  pulverizer. 

Statement:     Residue  of  seconds  800.     This,  abridged  by  the  common 

measure  eighty,  becomes  10.     Making  this  additive  ;  divisor  in  least  terms, 

137,  dividend ;  and  the  multiplier,  which  serves  to  bring  out  seconds,  namely 

sixty,  the  divisor;  the  statement  is  Dividend  137      *  j  i-^-  .    ,^       Here,  by 

Divisor       60     '^       '  '^^      " 

reciprocal  division  the  the  quotients  are  0      Residue  a.     This  is  multiplied 

S 

3 

1 

1 
by  a  multiplier  assumed  such,  that  the  product  with  one  added  may  be  ex- 
actly divisible,  since  the  residue  of  seconds  is  additive  :  but,  as  the  quotients 
are  here  uneven,  one  must  be  subtracted,  [§  13].  Such  an  assumed  multi- 
plier is  nine;  and  the  quotient  10.  Hence,  as  before,  the  constant  pulverizer 
is  deduced.  This  being  multiplied  by  the  residue  of  seconds,  namely  10, 
and  divided  by  its  divisor,  viz.  60,  the  residue  is  the  multiplier  10.  So  many 
are  the  seconds.  The  dividend  being  multiplied  by  the  multiplier,  and 
having  the  additive  added,  and  being  divided  by  sixty,  the  quotient  is  23. 
This  is  residue  of  minutes.     Again,  make  this  additive,  days  in  least  terms 

dividend,   and   sixty  divisor:     See  Dividend   137     a  \  ]\- r    oq       Hence, 

1  visor        oO 

proceeding  as  before,  the  multiplier  is  41.     So  many  are  the  minutes  past. 

The  dividend  being  multiplied  by  the  multiplier  41,   having  the  additive 

added,  and  being  divided  by  sixty,  the  quotient  is  residue  of  degrees,  94. 

Again,  this  is  put  additive,  days  in  least  terms  dividend,  and  thirty  di\isor. 

See   Dividend  137     A  j/litive  O-l      Hence,  as  before,   the  multiplier  comes 
Divisor        30  ^  ' 

out  28.     So  many  are  the  degrees.     The  dividend  being  multiplied  by  the 


Section  I.  PULVERIZER.  337 

multiplier,  having  the  additive  added,  and  being  divided  by  thirty,  the  quo- 
tient is  the  residue  of  signs  131.     Make  this  again  additive,  days  in  least 

■terms  dividend,  and  twelve  divisor;    [Dividend  137     Allitivel^ll     '^'^*^' 

Divisor        12  '-'  r 

multiplier  is  found  5.     So  many  are  the  signs  past.     The  dividend  being 

multiplied  by  the  multiplier,  and  having  the  additive  131  added,  and  being 

divided  by  twelve,  the  quotient  is  the  residue  of  revolutions,  68.     Put  days 

in  least  terms  for  dividend,  revolutions  in  least  terms  for  divisor,  and  residue 

of  revolutions  for  additive.     See:  Dividend  137      \  ],]>•  p  fio     Hence,  as 

Divisor         5 

before,  the  multiplier  comes  out  1.     This  is  the  [number  of]  revolutions 

past.     The  quotient  is  the  number  of  [elapsed]  days,  41. 

From  the  same  residue  put  as  an  assumed  one,  the  number  of  [elapsed] 
days,  in  like  manner,  comes  out  41. 

Here  an  arbitrary  multiple  of  137  is  additive. 

28.     Question  10.     He,  who  knows  the  elapsed  [portion  of  a]  7/uga  from 
the  residue  of  exceedmg  months  told,  or  assumed,  or  from  the  residue  of 
fewer  days,  or  from  the  sum  of  them,  is  a  person  versed  in  the  pulverizer. 

Example:  When  the  residue  of  e.t'ceei^^/wo"  months  is  eight  hundred  and 
eighty;  and  that  o^ fewer  days  seven  thousand  seven  hundred  and  twenty, 
and  the  sum  of  these  sixteen  thousand  two  hundred;  tell,  from  any  one  of 
these,  the  elapsed  [portion  of  the]  yuga. 

Residue  of  e.rceeJ/wg- months  8480.  Residue  of  ^/e^c/ew?  days  7720.  Sum 
16200. 

The  remainder,  which  is  found  by  the  rule  §  7,  [being  divided  by]  residue 
of  exceeding  months  arising  for  one  day,'  is  the  elapsed  solar  days  of  the  yuga. 
Proceeding  in  this  manner,  they  come  out  848. 

Or  else  let  exceeding  months  be  the  multiplier,  and  solar  days  be  the  divi- 
sor, and  the  constant  pulverizer  be  found  by  the  rule  §  9-  Residue  of  ex- 
ceeding months  is  to  be  multiplied  by  tliat.  Then  divide  the  product  by  the 
particular  divisor.     The  residue  is  solar  days. 

In  like  manner,  from  the  residue  of  deficient  days,  the  elapsed  lunar  days 
of  the  yuga  are  found  293. 

'  Daily  increment  of  the  difference  between  lunar  and  solar  months. 

X  X 


338  BRAHMEGUPTA.  Chapter  XVIII. 

From  the  sum  of  the  residues  of  more  months  and  fewer  days,  as  arising 
for  one  day,'  and  from  the  sum  of  tlie  residues  of  more  months  and  fewer 
days,  as  proposed,  and  reduced  to  lunar  days,  proceeding  by  the  rule  \  12,  tl)e 
lunar  days  are  to  be  found  108. 

29.  Question  11.  When  does  the  square-root  of  three  less  than  residue 
of  exceeding  months,  being  increased  by  two,  and  then  divided  and  lessened 
by  two,  and  squared,  and  augmented  by  nine,  amount  to  ninety? 

30.  Question  12.  When  does  the  square  of  deficient  days,  being  lessened 
by  one,  and  divided  by  twenty,  and  augmented  by  two,  and  multiplied  by 
eight,  and  divided  by  ten,  and  increased  by  two,  amount  to  eighteen? 

Here  proceeding  by  the  rule  of  inverse  process  as  before  taught,  the  resi- 
dues of  more  months  and  fewer  days  come  out  4099  and  I9. 

'  Daily  increment  of  the  difference  between  lunar  and  terrestrial  days. 


I 


(    339     ) 


SECTION  II. 


ALGORITHM.' 

lb 

31.  Rule  for  addition  of  affirmative  and  negative  quantities  and  cipher: 
§  19.  The  sum  of  two  affirmative  quantities  is  affinnative;  of  two  negative 
is  negative;  of  an  affirmative  and  a  negative  is  their  difference;  or,  if  they 
be  equal,  nought.  The  sum  of  cipher  and  negative  is  negative;  of  affirma- 
tive and  nought  is  positive;  of  two  ciphers  is  cipher. 

32 — 33.  Rule  for  subtraction :  §20 — 21.  The  less  is  to  be  taken  from 
the  greater,  positive  from  positive;  negative  from  negative.  When  the 
ffreater,  however,  is  subtracted  from  the  less,  the  difference  is  reversed. 
Negative,  taken  from  cipher,  becomes  positive;  and  affirmative,  becomes  ne- 
gative. Negative,  less  cipher,  is  negative;  positive,  is  positive;  cipher, 
nought.  When  affirmative  is  to  be  subtracted  from  negative,  and  negative 
from  affirmative,  they  must  be  thrown  together. 

34.  Rule  for  multiplication :  §  22.  The  product  of  a  negative  quantity 
and  an  affirmative  is  negative;  of  two  negative,  is  positive;  of  two  affirma- 
tive, is  affirmative.  The  product  of  cipher  and  negative,  or  of  cipher  and 
affirmative,  is  nought;  of  two  ciphers,  is  cipher. 

35 — 36.  Rule  for  division:  §23 — 24.  Positive,  divided  by  positive,  or 
negative  by  negative,  is  affmnative.  Cipher,  divided  by  cipher,  is  nought. 
Positive,  divided  by  negative,  is  negative.     Negative,  divided  by  affirmative, 

'  Shcd-trmsat-paricarman.  Thirty-six  operations  or  Qiodes  of  process.  See  Arithm.  §  1.  Vij-' 
gem.  H  3. 

X  X  2 


340  BRAIIMEGUPTA.  Chapter  XVIII. 

is  negative.  Positive,  or  negative,  divided  by  cipher,  is  a  fraction  with  that 
for  denominator:*  or  cipher  divided  by  negative  or  affirmative.' 

[36  Concluded.]  Rule  for  involution  and  evolution:  §  24..  The  square 
of  negative  or  affirmative  is  positive;  of  cipher,  is  cipher.  The  root  of  a 
square  is  such  as  was  that  from  which  it  was  [raised].' 

37.  Rule  of  concurrence  and  dissimilar  operation:  §25.  The  sum,  with 
difference  added  and  subtracted,  being  divided  by  two,  is  concuiTcnce.  The 
difference  of  squares  divided  by  [simple]  diflt'erence,  having  difference  added 
and  subtracted  and  being  then  divided  by  two,  is  dissimilar  operation.* 

38.  Rule  for  the  construction  of  a  rectangular  figure  with  rational  sides: 
§  26.  Be  a  surd  the  perpendicular.  Its  square,  divided  by  an  assumed  num- 
ber, has  the  arbitrary  quantity  added  and  subtracted.  The  least  is  the  base: 
and  half  the  greater  number  is  the  flank.^  Those  [surds'],  the  product 
whereof  is  a  square,  are  to  be  abridged. 

•  39.  Rule  for  addition  and  subtraction  of  surds:  §27-  The  surds  being 
divided  by  a  quantity  assumed,  and  the  square-roots  of  the  quotients  being 
extracted,  the  square  of  the  sum  of  the  roots,  being  divided  by  the  assumed 
quantity,  [is  the  sum,]  or  the  square  of  their  difference,  [so  divided,  is  the 
difference  of  the  surds]. 


■  Tach-ch'Mda,  having  that  for  denominator  :  having,  in  this  instance,  cipher  for  denominator, 
to  a  finite  quantity  for  numerator.     See  Vij.-gan.  §  l6. 

■   *  Is  in  like  manner  expressed  by  a  fraction  having  a  finite  denominator  to  a  cipher  for  nurae- 
Tator. 

^  The  root  is  to  be  taken  either  negative  or  affirmative,  as  best  answers  for  the  further  operations. 

Com. 

♦  Vishama-carman.     See  Lil.  §  57. 

'  Let  the  perpendicular  be  put  an  irrational  number  8 ;  and  let  the  assumed  number  be  4. 
Hence  the  figure  is  constructed 


12 
'  Surd  is  understood  from  the  preceding  sentence.    Those  irrationab  are  to  be  abridged,  the 
product  of  pairs  of  which  is  a  square.  Com. 


Section  II.  LOGISTICS.  341 

Example :  Tell  the  sum  and  difference  of  surds  two  and  eight,  and  three 
and  twenty-seven,  respectively. 

Statement:  c2  c8.  These  surds,  divided  by  an  assumed  number  2,  give 
I  and  4;  the  roots  whereof  1  and  2.  The  squares  of  their  sum  and  difference 
are  9  and  1;  which,  multiplied  by  the  assumed  number,  become  18  and  2, 
the  sum  and  difference  of  the  surds, 

Statement  of  the  second  Example:  c3  c27.  Proceeding  as  above,  the 
sum  and  difference  are  found  48  and  12. 

[39  Concluded.]  Rule  of  multiplication :  §  27-  The  multiplicand  is  put 
level  with  the  [terms  of  the]  multiplicator  [placed]  across,  one  under  the 
other;  and  their  products  are  added  together. 

Example  :*  The  multiplicator  comprises  the  surds  two,  three  and  eight ; 
and  the  multiplicand,  three  with  the  rational  number  five.  Tell  the  product 
quickly.  Or  let  the  multiplicator  consist  of  the  surds  three  and  twelve  less 
the  rational  number  five. 

Statement:  Multiplicator  c 2  c3  c8.     Multiplicand  c 3  ru5. 
Here  multiplicand  is  placed  level  with  the  terms  of  the  multiplicator 
across,  one  under  the  other: 

Multiplier.  Multiplicand.                         Product. 

c2  c  3     ru5  c   6     c    50 

c3  c3     ru5  c   9     c    75 

c8  c5     ru5  c  2,4,     c  200 

Summing  the  products  as  directed  by  the  rule,   the  answer  comes   out 

ru  3   c  450   c  75    c  54. 

i 

Statement  of  the  second  Example :  Multiplicand  c3  ru5.  Multiplier 
c  3    c  12    ru5. 

Proceeding  as  before,  the  result  of  multiplication  is  rw  l6   c  300. 

40.     Rule  of  division  of  surds:  §  28.     The  dividend  and  divisor  are  mul- 
'  End  of  one  couplet  and  beginning  of  another. 


342  BRAHMEGUPTA.  Chapter  XVIII. 

tiplicd  by  the  divisor  witli  a  selected  [term]  made  negative;*  and  are  seve- 
rally summed :  more  than  once  [if  occasion  there  be].  The  dividend  is  then 
divided  by  the  divisor  reduced  to  a  single  term. 

Statement  of  the  foregoing  result  of  multiplication  as  dividend,  and  its 

multiplier  as  divisor,  for  division :  ru  3    c  450    c  75    c  54. 

cl8*  c3 

Put  cl8   c3.      The  dividend    and  divisor,   multiplied   by   this,   make 
ru75    c625.     The  dividend  being  then  divided  by  the  single  surd  consti- 
ru  15 
tuting  the  divisor,  the  quotient  is  rw  5    c  3. 

Statement  of  the  second  Example :  ru  16  c  300     Here  putting  the  surd 

c27   c    25 

twenty-seven  negative,  and  proceeding  as  before,  the  answer  comes  out 

ru  5    c  3. 

[40  Concluded.]  Rule  of  involution :  §28.  A  square  is  the  product  of 
two  like  quantities. 

Example :  Tell  the  square  of  the  surds  six,  five,  two  and  three. 

Statement:  c6  c5  c2  c3.  Answer:  rw  16  c  120  c  72  c  60  c  48 
c40   c24. 

41.  Rule  of  evolution :  §29.  From  the  square  of  the  absolute  number 
take  surds'  selected  at  choice.  The  square-root  of  the  difference  being 
added  to  and  subtracted  from  the  absolute  number,  the  moieties  are  treated, 
the  first  as  an  absolute  number,  the  second  as  a  [radical]  surd  exclusive  of 
the  rest.     More  than  once.* 

Example :  The  square  as  above  found  stated  for  extraction  of  the  root : 
ru  16   c  120   c  72    c  60   c  48   c  40  c  ^4. 

'  That  is  to  say,  among  the  surd  terms,  which  compose  the  surd  divisor,  one  is  selected  which 
though  affirmative  is  to  be  put  negative.  Com. 

•  Sum  of  c  2  and  c  8. 

*  One,  two  or  more  surd  terms.  '■>  '^'•''  '"^  Com. 

♦  Repeat  the  operation  so  long  as  there  remain  surd  terms  of  the  square.  Com. 


Section  II. 


LOGISTICS. 


343 


Subtract  the  three  surds  c  120  c7'I  c48  from  the  square  of  the  absolute 
number  256.  Remainder  \6.  Its  root  4.  Added  to  and  subtracted  from 
the  rational  number,  and  halved,  it  gives  10  and  6  as  two  surd  terms.  The 
first  is  treated  as  rational;  and  the  second  as  a  radical  surd.  Again,  sub- 
tracting two  surd  terms  60  and  24  from  the  square  of  the  rational  100,  the 
difference  is  l6;  of  which  the  square-root  is  4;  and  the  moieties  of  the  sum 
and  difference  are  7  and  3.  The  first  is  here  treated  as  absolute;  and  the 
second  as  a  radical  surd.  Again,  subtracting  the  surd  40  from  the  square  of 
the  absolute  49,  the  remainder  is  9,  of  which  the  square-root  is  3;  and  the 
moieties  of  sum  and  difference  are  5  and  2. 

Statement  of  the  radical  surds  in  order  aS'<^ound :  c6   c  5    c  3   c  Q. 

42.  Rule  of  addition  and  subtraction  of  unknown  quantities,  and  their 
squares,  &c.  §  30.  The  sum  and  difference  of  like  terms,  whether  unknown 
quantities,  or  squares,  cubes,  biquadrates,  fifth,  sixth,  &c.  powers,'  are  taken; 
but  if  dissimilar  are  severally  stated.  -i; 

43.  Rule  of  multiplication,  &c.  §31.  The  product  of  two  like  quanti- 
ties is  a  square;  of  three  or  more,  is  the  power  of  that  designation.*  The 
product  of  dissimilar  quantities,  the  symbols  being  mutually  multiplied,  is  z^ 
factum.^     The  rest  is  as  before. 


'  Pancha-gata,  fifth  power;  shad-gata,  sixth  power,  &c.     Literally  '  arrived  at  the  fifth,  &c. 
[degree] '. 

*  Tad-gat  a,  Tailed  to  thit.  ^. 

'  Bhivitaca,  OT  bhdvita.     See  V'lj.-gan,  Sil.  ]  ,9iol 


C    344    )  .oiroi"^- 

SECTION  III. 


r 


SIMPLE  EQUATION. 

-)(44.  Rule  for  a  simple  equation  :*  §  32.  The  difference  of  absolute  num- 
bers, inverted  and  divided  by  the  difference  of  the  unknown,  is  the  [value  of 
the]  unknown  in  an  equation.* 

45.     Question  13.     If  four  times  the  twelfth  part  of  one  more  than  the 
remainder  of  degrees,  being  augmented  by  eight,  be  equal  to  the  remainder  % 

of  degrees  with  one  added  thereto,  tell  the  elapsed  days. 

Here   remainder  of  degrees  is  put  yavat-tavat :    viz.  ya  1.      With  one 
added,  it  is  ya  \   ru  \.     Its  twelfth  part  is  ya  \   ru  \     This  quadrupled  is  | 

\^ 
ya  \  ru  \      Augmented  by  eight  absolute,  it  is  ya  1   ru  25      It  is  equal  to  ^ 

3  '  1    nj  o 

remainder  of  degrees  with  one  added  thereto.     Statement  of  both  sides 

tripled,  ya  1  ru  25      The  difference  of  [terms  of  the]  unknown  is  ya  2.     By 

ya  3  ru    3 
this  the  difference  of  absolute  number,  namely  22,  being  divided,  yields  the  i 

residue  of  degrees  of  the  sun  1 1 .  This  residue  of  degrees  must  be  under- 
stood to  be  in  least  terms.  The  elapsed  days  are  to  be  hence  deduced,  as  be- 
fore, (§7).  .  •  '' 


'  The  four  methods  of  analysis  (vija-chatushtaya)  are  next  explained ;  and  in  the  first  place 
equatjcn  of  a  single  colour.  Com.  ^ 

*  The  value  of  the  unknown  quantity,  in  the  example,  as  proposed  by  the  question,  is  to  be  put 
ydvat-tuvat ;  and,  upon  that,  performing  multiplicatiou,  division,  and  other  operations  as  requisite  } 

in  the  instance,  two  sides  are  to  be  carefully  made  equal.  The  equation  being  framed,  the  rule 
takes  effect.  Subtract  the  [term  of  the]  unknown  in  the  first  of  those  two  equal  sides  from  the  un- 
known of  the  second.  The  remainder  is  termed  difference  of  the  unknown.  The  absolute  number 
on  the  other  side  is  to  be  subtracted  from  the  absolute  number  on  the  first  side  :  and  the  residue  is 
termed  difference  of  the  absolute.  The  residue  of  the  absolute,  divided  by  the  remainder  of  the 
unknown,  is  the  value  of  the  unknown.  Com. 


I 


Section  III.  SIMPLE   EQUATION.  345 

46.  Question  14.  When  the  residue  of  exceeding  months,  less  two, 
being  divided  by  three,  having  seven  added  to  the  quotient,  and  then  mul- 
tipHed  by  two,  is  equal  to  the  residue  of  exceeding  months,  tell  the  elapsed 
days. 

Remainder  of  exceeding  months  ya  1.     Proceeding  with  this  as  said,  there 
results  ya  1    ru  38.     This  is  equal  to  the  remainder  of  exceeding  months 
3 

ya  \.     Statement  of  both  sides  of  equation  tripled  3/«  2    rw  38     By  the  fore- 

ya  3   ru    0 
going  rule  (§  32)  the  answer  comes  out,  residue  of  exceeding  mouths,  38. 
It  must  be  understood  to  be  in  least  terms;  and  from  it  elapsed  time  is  to  be 
deduced  as  before. 

47.  Question  15.  If  the  residue  of  deficient  days,  less  one,  being  divided 
by  six  and  having  three  added  to  the  quotient,  be  equal  to  the  residue  of 
deficient  days  divided  by  five,  tell  the  elapsed  period. 

Here  the  remainder  of  deficient  days  is  put  ya  1 ;  from  which,  as  before, 

results  j/a  1   ru  17.  It  is  equal  to  remainder  of  deficient  days  divided  by  five, 

6 
ya  J-.     The  two  sides  of  equation  being  reduced  to  a  common  denomination 

and  the  denominator  dropped,  the  statement  is  ya  5   ru  85      Hence,  as  bc- 

ya  6  ru    0 

fore,  the  residue  of  deficient  days  is  found  85 ;  from  which  elapsed  days  arc 

/deduced  as  before. 


V  y 


(     346     ) 

SECTION  IV. 


<IUADRATIC  EQUATION. 

48.'  Rule  for  elimination  of  the  middle  term  :*  §  32,  33.  Take  absolute 
number  from  the  side  opposite  to  that  from  which  the  square  and  simple  un- 
known are  to  be  subtracted.  To  the  absolute  number  multiplied  by  four 
times  the  [coefficient  of  the]  square,  add  the  square  of  the  [coefficient  of  the] 
middle  term ;  the  square  root  of  the  same,  less  the  [coefficient  of  the]  middle 
term,  being  divided  by  twice  the  [coefficient  of  the]  square,  is  the  [value  of 
the]  middle  term.' 

49.  Question  16.  When  does  the  residue  of  revolutions  of  the  sun,  less 
one,  fall,  on  a  Wednesday,  equal  to  the  square  root  of  two  less  than  the  resi- 
due of  revolutions,  less  one,  multiplied  by  ten  and  augmented  by  two? 

The  value  of  residue  of  revolutions  is  to  be  here  put  square  of  ydvat-tdvat 

with  two  added :  i/av  1  rM  2  is  the  residue  of  revolutions.     This  less  two  is 

ya  V  I ;  the  square  root  of  which  is  i/a  1.     Less  one,  it  is  i/a  \   ru  ]  ;   which 

multiplied  by  ten  is  ya  10  ru  10;  and  augmented  by  two  ya  10  ru  8.     It  is 

equal  to  the  residue  of  revolutions  i/a  v  \    ru  Q  less  one:  viz.  ya  v  1    ru  I. 

Statement  of  both  sides  ^^a  v  0  ya  ]0  rw  8      Equal  subtraction  being  made 

ya  V  \   ya    0  ru  1 

*  Remaining  half  of  a  couplet  and  one  whole  one. 

^  Mad'hyam&harana.     See  Vy.-gan.  Ch.  1. 

■  An  equation  of  two  sides  being  framed  conformably  to  the  enunciation  of  the  instance,  if  there 
be  a  square  or  other  [power]  together  with  the  unknown,  then  this  rule  takes  effect.  Subtract  the 
absolute  number  from  the  side  other  than  that  from  which  the  square  and  the  unknown  qualities 
are  subtracted.  Then  equal  subtraction  having  been  so  made,  the  numeral  (anca)  which  belongs  to 
the  square  of  the  unknown,  is  termed  [coefficient  of  the]  square;  and  that,  which  appertains  to  the 
unknown,  is  called  [coefficient  of  the]  middle  term.  The  absolute  number,  which  is  on  the  second 
side,  being  multiplied  by  four  times  the  square  [i.  e.  its  coefficient]  and  added  to  the  square  of  the 
middle  term  [i.  e.  of  its  coefficient],  the  square-root  of  the  sum,  less  the  middle  term  [i.  c.  its  co- 
efficient], divided  by  the  double  of  the  square  as  it  is  termed  [i.  e.  coefficient],  is  the  middle  term ; 
that  is  to  say,  it  is  the  value  of  the  unknown.  Com. 


SectionIV.         quadratic    equation.  347 

conformably  to  rule  (§  32)  there  arises  ru  9     Now,  from  the  abso- 

yax)  \  ya  10 
lute  number  (9),  multiplied  by  four  times  the  [coefficient  of  the]  square  (36), 
and  added  to  (100)  the  square  of  the  [coefficient  of  the]  middle  term,  (making 
consequently  64),  the  square  root  being  extracted  (8),  and  lessened  by  the 
[coefficient  of  the]  middle  term  (10),  the  remainder  18  divided  by  twice  the 
[coefficient  of  the]  square  (2),  yields  the  value  of  the  middle  term  9.  Sub- 
stituting with  this  in  the  expression  put  for  the  residue  of  revolutions,  the 
answer  comes  out,  residue  of  revolutions  of  the  sun  83.  Elapsed  period 
of  days  deduced  from  this,  393,  must  have  the  denominator  in  least  terms 
added  so  often  until  it  fall  on  Wednesday. 

50.  Or  another  Rule:  §  34.  To  the  absolute  number  multiplied  by  the 
[coefficient  of  the]  square,  add  the  square  of  half  the  [coefficient  of  the]  un- 
known, the  square  root  of  the  sum,  less  half  the  [coefficient  of  the]  unknown, 
being  divided  by  the  [coefficient  of  the]  square,  is  the  unknown. 

In  the  foregoing  example,  equal  subtraction  being  made  from  the  two 
sides,  the  result  was_ya  v  \  ya  \iy  Here  absolute  number  (9)  multiplied 

by(l)  the  [coefficient  of  the]  square  (9),  and  added  to  the  square  of  half  the 
[coefficient  of  the]  middle  term,  namely,  25,  makes  l6 ;  of  which  the  square 
root  4,  less  half  the  [coefficient  of  the]  unknown  (5),  is  9;  and  divided  by  the 
[coefficient  of  the]  square  ( 1 )  yields  the  value  of  the  unknown  9 .  S  ubstituting 
with  this,  the  residue  of  revolutions  comes  out  83:  whence  elapsed  days  are 
deduced,  as  before,  39^. 

51.  Question  17-  When  is  the  square  of  three  less  than  the  quarter  of  the 
residue  of  exceeding  months  equal  to  the  residue  of  exceeding  months  ?  or 
the  like  [function]  of  remainder  of  deficient  days  equal  to  remainder  of  defi- 
cient days? 

Remainder  of  exceeding  months  is  here  put  ya  4.  Its  quarter  less  three  is 
ya  \  ru  3;  of  which  the  square  is  ya  v  I  ya  6  ru  9-  It  is  equal  to  the  re- 
mainder of  exceeding  months.  The  process  being  performed  as  before,  the 
residue  of  exceeding  months  is  found  4.  Whence  the  elapsed  period  is  de- 
duced. 

In  like  manner  the  remainder  of  deficient  days  likewise  is  4:  whence  the 
elapsed  period  comes  out  1031. 

Y  Y  3 


(     348     ) 

SECTION  V. 


EQUATION  OF  SEVERAL  COLOURS. 

52.  Rule:  §  35.  Subtracting  the  colours  other  than  the  first  from  the 
opposite  side  to  that  from  which  the  first  is  subtracted,  after  reducing  them 
to  a  common  denomination,  the  vakie  of  the  first  is  derived  from  [the  residue] 
divided  by  this  [coefficient  of  the]  first.  If  more  than  one  [value],  two  and 
two  must  be  opposed.  The  pulverizer  is  employed,  if  many  [colours]  re- 
main.* 

53.  Question  18.  He,  who  tells  the  number  of  [elapsed]  days  from  the 
number  of  days  added  to  past  revolutions,  or  to  the  residue  of  them,  or  to  the 
total  of  these,  or  from  their  sum,  is  a  person  versed  in  the  pulverizer. 

Example:  The  number  of  [elapsed]  days  together  with  past  lunar  revolu- 
tions is  given  equal  to  one  hundred  and  thirty-nine.  Tell  me  the  number  of 
days  separately. 

Here  the  number  of  [elapsed]  days  is  put  j/a  1.     Multiplied  by  revolutions 

*  In  an  example  in  which  there  are  two  or  more  unknown  quantities,  two  or  more  colours,  a* 
y&vat-t&vat,  &c.  must  be  put  for  their  values  :  and  upon  those  the  requisite  operations,  conformably 
to  the  instance,  being  wrought,  two  or  more  sides  of  equation  are  to  be  carefully  framed :  and 
among  them,  taiten  two  and  two,  equal  subtraction  is  to  be  made  ;  in  this  manner :  the  first  colour 
being  subtracted  from  one  side,  subtract  the  rest  of  the  colours  reduced  to  a  like  denomination,  and 
absolute  number,  from  the  other  side.  The  residue  of  another  colour  being  divided  by  the  residue 
of  the  first,  the  quotient  is  a  value  of  the  first  colour.  If  many  such  values  be  obtained,  they  must 
be  equated  again  in  pairs  reducing  them  to  like  denominators.  But,  that  being  done,  if  there  be 
two  colours  in  the  value  of  another  colour  which  is  thence  deduced,  the  coefficients  (anca)  of  those 
two  are  reciprocally  the  values  of  such  colours.  But,  if  there  be  many  colours  in  the  value  of 
another  colour,  the  pulverizer  must  be  applied  to  them  ;  in  this  manner :  excepting  one  colour, 
substitute  arbitrary  values  for  the  rest,  and,  adding  them  to  absolute  number,  form  the  addition. 
Make  the  coefficient  of  the  selected  colour,  the  dividend  ;  and  the  coefficient  of  the  colour  in  the 
denominator,  the  divisor.  The  multiplier,  hence  found  by  the  method  of  the  pulverizer,  is  the 
value  of  the  colour  in  the  dividend ;  and  the  quotient  is  the  value  of  that  in  the  divisor.       Com. 


Sect.  V.      EQUATION  INVOLVING  SEVERAL  UNKNOWN.    349 

of  the  moon  in  least  terms,  and  divided  by  the  divisor  also  reduced  to  the. 
least  terms,  there  results  3/ff  -^-f-^;  from  which  less  the  residue  of  revolutions, 
divided  by  the  divisor,'  the  quotient  is  the  [complete]  revolutions;  where- 
fore the  residue  of  revolutions  is  put  ca  1.  Less  that,  and  divided  by  the 
divisor  in  least  terms,  it  yields  revolutions,  ya  5    ca  ] ;  which,  added  to  the 

137 
number  of  [elapsed]  days,  makes  3/rt  142    ca  I.     It  is  equal  to  the  sum  of 

137 
[complete]  revolutions  and  immber  of  [elapsed]  days,  rw  139.     Statement  of  both 
sides  of  equation  reduced  to  the  same  denominator,  ^fl  142    ca  \     r?<  0        '^ 

ya  0        ca  0   i-u  19013 
Subtraction   being  made   as   prescribed   by   the   rule  (§  35),  the   result  is 

ca  1  ru  19043.  Since  there  are  several  colours,  the  pulverizer  nmst  be 
ya  142 

employed.  The  coefficient  of  the  colour  in  the  dividend  is  dividend;  that 
which  stands  with  the  colour  in  the  divisor,  is  divisor.  From  these  the  con- 
stant pulverizer,  as  found  by  the  rule  (§  9),  is  141.  Multiplying  by  this  the 
additive  19043,  divide  by  the  divisor  142,  the  residue  is  here  the  multiplier 
sought,  127.  It"  is  the  value  of  cdlaca.  The  dividend  being  multiplied  by 
the  multiplier,  and  having  the  additive  added,  and  being  divided  by  its  divi- 
sor, the  quotient  is  the  value  of  ydvat-tdvat,  135.  It  is  the  number  of 
[elapsed]  days. 

Example:  When  the  residue  of  lunar  revolutions,  with  the  number  of 
[elapsed]  days,  is  given  equal  to  two  hundred  and  sixty-two,  tell  me  the 
number  of  days. 

The  number  of  [elapsed]  days  is  here  put  ya  1.  This,  multiplied  by  revo- 
lutions and  divided  by  the  divisor,  becomes  j/a  5.     Then  cdlaca  is  put  for  the 

value  of  quotient.'^  If  the  divisor  multiplied  by  the  quotient  be  subtracted 
from  the  number  of  elapsed  days  multiplied  by  the  [periodical]  revolutions, 
the  residue  which  remains  is  the  residue  of  revolutions.     So  doing,  the  result 


'  So  the  original:  but  the  expression  is  not  quite  accurate,  as  the  fraction  is  not  again  divided; 
but  the  multiple  of  the  time  by  periodical  revolutions,  less  the  residue,  being  divided,  gives  tiie 
complete  revolutions  for  quotient. 

*  Exclusive  of  the  fractional  residue. 


350  BRAHMEGUPTA.  Chapter  XVIII. 

isi/a5    ca  137.     This,  with  the  number  of  days,  becomes  3/rt  6    ca  \37.     It 

is  equal  to  the  sum  of  the  number  of  days  and  residue  of  revolutions,  262. 

Statement  of  both  sides  of  equation    i/a  6     ca  1 37     ru  0  The  process 

ya  0     ca  0         I'u  26S 

being  followed  as  before,  the  multiplier  comes  out  4.     It  is  the  value  of 

cdlaca.     The  quotient  is  the  value  of  ydvat-tdvat,  135.     It  is  the  number  of 

[elapsed]  days. 

Example :  If  the  sum  of  the  three  specified  articles  be  equal  to  two 
hundred  and  sixty-six,  tell  me  the  number  of  [elapsed]  days;  or  tell  it  from 
the  sum  of  the  other  two. 

The  specified  articles  are  [complete]  revolutions,  the  residue  of  them,  and 

the  number  of  days.     The  number  of  days  isputyal.     This,  multiplied  by 

revolutions  and  divided  by  the  divisor,  is  i/a  -^4^.     The  quotient'  is  ca  1. 

Divisor    multiplied    by    quotient,    being   subtracted   from   the  number  of 

[elapsed]  days  taken  into  revolutions,  the  remainder  is  residue  of  revolutions, 

ya  5    ca  137-     Adding  the  number  of  days  and  the  [past]  revolutions,  the 

total  is  ya  6   ca  136.     This  is  equal  to  the  sum  of  the  number  of  [elapsed] 

days,  the  residue  of  revolutions  and  [past]  revolutions,  266.     Statement  of 

the  two  sides  of  equation,  ya  6    ca  136    ru  0         Hence,  by  equal   sub- 

ya  0    ca  0        ru  266 

traction  and  other  process,  as  before,  the  constant  pulverizer  comes  out  2; 
and  the  multiplier  is  found  4.  It  is  the  value  of  cdlaca;  and  is  the  [number 
ofj  past  revolutions  4.  The  quotient  is  the  value  of ydvat-tdvat,  135.  It 
is  the  number  of  [elapsed]  days.  Subtracting  the  sum  of  [past]  revolutions 
and  [elapsed]  days  from  the  sum  total,  the  remainder  is  the  residue  of  revolu- 
tions, 127. 

Example  :  When  the  residue  of  revolutions  of  the  moon  added  to  the  re- 
volutions past  is  equal  to  one  hundred  and  thirty-one,  tell  me  the  number  of 
[elapsed]  days. 

Number  of  days  3/a  1.  The  residue  of  revolutions  is  found  as  before 
ya  5  ca  \  37.  This,  added  to  past  revolutions,  is  ya  5  ca  1 36.  It  is  equal 
to  the  sum  of  past  revolutions  and  residue  of  revolutions,  131.  The  con- 
stant pulverizer  comes  out  4.     Hence  the  multiplier,  4.     It  is  the  value  of 

'  Exclusive  of  the  fractional  residue. 


Sect.  V.     EQUATION  INVOLVING  SEVERAL  UNKNOWN.     351 

calaca  as  before;  and  is  the  number  of  revolutions  complete.     The  quotient 
is  the  value  o^ydvat-tdvat,  135.     It  is  the  number  of  [elapsed]  days. 

54.  Question  I9.  He,  who  tells  the  number  of  [elapsed]  days  from  the 
number  of  days  less  the  past  revolutions,  or  less  the  residue  of  them,  or  less 
the  sum  of  these,  or  from  their  difference,  is  a  person  acquainted  with  the 
pulverizer. 

Example :  The  number  of  [elapsed]  days,  less  the  past  lunar  revolutions, 
is  given  equal  to  one  hundred  and  thirty-one ;  tell  me  the  number  of  days. 

Here  tiie  value  of  the  number  of  days  h  ya\;  Avhich,  being  multiplied  by 
revolutions,  and  lessened  by  residue  of  revolutions,  put  equal  to  cdlaca,  and 
divided  by  its  divisor,  becomes  the  number  of  past  revolutions,  ya  5    ca  \. 

137 
The  number  of  days,  less  that,  is  ya  \32    ca  \.     It  is  equal  to  the  difference 

137 
between  the  number  of  days  and  past  revolutions,  namely,  131.     Statement 
of  the  equation  reduced  to  a  common  denominator,  ya  1 32    ca  \    ru  0 

ya  0  ca  0  ru  1 7947 
Equal  subtraction  being  made,  as  before,  the  constant  pulverizer  comes  out 
133.  The  multiplier,  value  of  cdlaca,  127-  The  quotient  is  the  value  of 
ydvat-tdvat :  it  is  the  number  of  [elapsed]  days,  1 35.  The  difference  be- 
tween the  number  of  days  and  past  revolutions,  131,  being  subtracted,  the 
remainder  is  the  past  revolutions,  4. 

Example :  [Elapsed  days]  less  the  residue  of  the  [revolutions]  being  eight; 
or  less  the  sum  of  the  [past  revolutions  and  their  residue]  being  four;  or  less 
the  difference  of  the  two  being  a  hundred  and  twenty-three:  tell  the  num- 
ber of  [elapsed]  days. 

In  the  first  example,  the  value  of  the  number  of  [elapsed]  days  is  put_y«  1. 
As  before,  the  residue  of  revolutions,  ya  5  ca  137.  Taking  this  from  the 
number  of  days,  the  remainder  is  ya  4  ca  137.  It  is  made  equal  to  eight; 
and  proceeding,  as  before,  the  multiplier  or  value  of  cdlaca  is  4;  and  the 
value  of  ydvat-tdvat,  or  number  of  [elapsed]  days,  135. 

In  the  second  example,  residue  of  revolutions,  as  before,  ya  5  ca  1 37- 
Past  revolutions  ca  1.     Their  sumj^a  5    ca  136.     This,  subtracted  from  the 


352  BRAHMEGUPTA.  Chapter  XVllI. 

number  of  clays,  leaves  j/fl  4  ca  \  36.  It  is  equal  to  four.  The  result  is 
value  o{  cdtaca,  4;    and  value  oi'  ydvat-tdrat,  the  number  of  days,  135. 

In  the  third  example,  residue  of  revolutions,  i/a  5  ca  137.  Past  revolu- 
tions, ca  1.  Difference  ^a  5  ca  138.  It  is  equal  to  one  hundred  and  thirty- 
three.  The  result  is,  value  of  cdlaca,  4:  \a\uc  of  ydvat-tdvat,  the  number  of 
days,  135. 

55.  Question  20.  He,  who  tells  the  elapsed  [portion  of  the]  cycle  from 
the  signs,  or  the  like;'  or  the  residues  of  them;  or  from  past  exceeding 
months;  or J'ewer  days;  or  their  residues,"  is  a  person  conversant  with  the 
pulverizer. 

'  Example  :  Forty-six,  a  hundred  and  seventy-two,  a  hundred  and  seventy- 
seven,  and  a  hundred  and  thirty-six,  are  declared  to  be  respectively  the 
amount  of  the  number  of  [elapsed]  days  added  to  past  signs ;  or  to  the  residue 
of  them;  or  to  the  sum  of  these  two;  or  amount  of  the  sum  of  the  two:  tell 
me  the  number  of  days  in  the  several  instances. 

Here  the  residue  of  lunar  revolutions  is,  as  before,  j/a  5  ca  137.  This, 
multiplied  by  twelve,  becomes  ya  60  ca  1644.  Subtracting  from  it,  tlie 
residue  of  signs  denoted  by  nilaca,  and  dividing  by  the  divisor,  and  adding 
the  number  of  [elapsed]  days,  the  result  \&  ya  197   ca  16'44    ni  \.     It  is  equal 

137 
to  forty-six.     Statement  of  the  two  sides  of  equation  reduced   to  a  like 

denomination,  ya  197  ca  1644  ni  1    ru  0         Equal  subtraction  being  made, 
ya  0       ca  0         ni  0    ru  6302 

the  value  of  ydvat-tdvat  is  ca  1644   ni  1    ru  630!iJ.     Here  the  arbitrary  value 

'  Degrees,  minutes,  or  seconds.  Com. 

*  As  four  problems  were  proposed  in  the  preceding  passage,  (Question  18,)  so  are  four  to  be 
here  understood  for  finding  the  number  of  [elapsed]  days  from  the  number  of  days  added  to  past 
signs;  or  added  to  the  residue  of  them;  or  to  the  total  of  these  [signs  and  residue];  or  from  the 
sura  of  these  two.  And,  as  four  problems  were  proposed  in  the  foregoing  passage,  (Question  19,) 
so  are  four  to  be  inferred  for  finding  the  same  from  the  number  of  days,  less  the  past  signs,  and  so 
forth.  Thus  the  problems  are  eight.  In  like  manner,  from  past  degrees  and  their  residue;  from 
past  minutes  and  their  residue  ;  from  past  seconds  and  their  residue  ;  eight  problems,  in  each  in- 
stance, are  to  be  deduced  :  and  as  many  in  each  case  of  pa.<>t  exceeding  months,  and  deficient  days, 
n^d  the  residues.  Com. 


Sect.  V.    EQUATION  INVOLVING  SEVERAL  UNKNOWN.  353 

of  nilaca  is  assumed  such,  that  no  defect  may  ensue:  say  131.  This  is  resi- 
due of  signs.  Multiplying  by  it  [the  coefficient  of]  nilaca,  and  adding  [the 
product]  to  the  absolute  number,  the  pulverizer  is  deduced,  1 :  it  is  the  value 
of  cdlaca;  that  is,  the  past  revolutions.  The  quotient  is  the  value  of  ydvat- 
tdvat,  and  is  the  number  of  [elapsed]  days,  41. 

In  the  second  example,  multiplying  by  twelve  the  residue  of  revolutions, 
subtracting  signs  multiplied  by  their  divisor,  the  residue  of  signs  is  obtained 
ya60  ca  1644  ««  137-  Adding  to  this  the  number  of  [elapsed]  days,  and 
making  the  sum  equal  to  one  hundred  and  seventy-two,  the  statement  of  the 
equation  is  ya6\    ca  1644   ni  137   ruO       Subtraction  being  made  and  the 

yaO      caO         niO       ru  \  72 
value  of  nilaca  being  assumed  five,  the  pulverizer  is  deduced,  1 .     It  is  the 
value  of  cdlaca.     The  quotient  is  the  value  of  ydvat-tdvat ;  and  is  the  num- 
ber of  [elapsed]  days,  41. 

In  the  third  example,  past  signs  are  ya  60  ca  1644   ni  1.    Adding  residue 

137 
of  signs,  the  sum  isyaGO   ca  1644   nilS6;  to  which  adding  the  number  of 

137 
[elapsed]  days,  the  result  is  ya  197   ca  1644   ni  136.     This  is  equal  to  a  hun- 

137 
dred  and  seventy-seven  [to  be]  reduced  to  a  common  denomination.     Putting 
131  for  the  value  of  nilaca,  and  by  means  of  the  pulverizer,  the  number  of 
days  comes  out  41. 

In    the    fourth    example,     the    sum    of   past    signs    and    residue    is 
ya  60  ca  1644   ni  136.     It  is  equal  to  a  hundred  and  twenty-six  [to  be] 

137 
reduced  to  the  like  denomination.     With  this  value  of  nilaca  131,  the  mul- 
tiplier is  deduced,  2.     The  quotient  is  the  number  of  days,  41.     Or  else  178 ; 
or  315.     The  like  is  to  be  understood  also  in  the  case  of  revolutions  and  the 
rest. 

When  the  number  of  days  less  the  [complete]  signs  is  given,  what  is  the 
'  number  of  days?    Here,  as  before,  the  [complete]  signs  are  j/a  60  ca  1644  nil. 

137 
The  number  of  days,  less  that,  is  5^a77   ca  1644   ni  1.     This  is  equal  to  si 

137^ 
z  z 


354 


BRAHMEGUPTA. 


Chapter  XVIII. 


hundred  and  twenty-four.*  Nilaca  being  assumed  seventeen,  the  multiplier 
is  deduced  4;  and  the  quotient  135.     It  is  the  number  of  days. 

In  the  second  example,  residue  of  signs  ya60  ca  1644  ni  137.  Sub- 
tracting this  from  the  number  of  days,  the  remainder  is  ya  59  ca  1644  ni  137. 
It  is  equal  to  a  hundred  and  eight.  Eleven''  being  put  for  nilaca,  the  multi- 
plier comes  out  4;  and  the  quotient  135.  This  is  the  number  of  [elapsed] 
days. 

In  the  third  example,  sum  of  past  signs  and  residue  _ya  60  ca  1644  ni  136. 

137 
The  number  of  days,  less  that,  is  ya  77   ca  1644   ni  136.     It  is  equal  to  a 

137 
hundred  and  seven.     Nilaca  being  assumed  seventeen,  the  multiplier  comes 
out  4;  and  the  quotient,  or  number  of  days,  135. 

In  the  fourth  example,  past  signs  ya60   ca  1644   ni  1.     Residue  of  signs, 

137 
ni  1.  Difference  of  these  reduced  to  like  denominators,  ya60  ca  1644  ?ii  138. 

m 

It  is  equal  to  six.  Subtraction  being  made  on  both  sides,  and  seventeen 
being  arbitrarily  put  for  nilaca,  the  multiplier  is  found  4;  and  the  quotient, 
or  number  of  days,  135. 

Next,  from  the  sum  of  past  degrees  and  number  of  [elapsed]  days,  [the 

elapsed  time  is  to  be  sought].     Here,  as  before,  the  residue  of  signs  is 

ya60  ca  1644    ni'137-     Multiplying  this  by  thirty,  subtracting  residue  of 

degrees  put  equal  to  pitaca,  and  dividing  by  the  divisor,  the  quotient  is  past 

!  degrees,  which  thus  come  out  ya  1800  cfl  49320   n/4110  pi  1.     The  uum- 

137 
her  of  days  being  added,  the  sum  is  equal  to  21,  the  assumed  amount  of 
degrees    and  number    of   days.      Subtraction    being   made    on   the  two 
sides    of  equation    reduced    to    a    common    denominator,    the    result    is 
ca  49320   WJ4110  pi  1    rw  2877.     Here  substituting  with  four  for  nilaca, 

(ya)  1937 
and  with  fifty-three  for  pitaca,  and  adding  the  values  so  raised  to  the  absolute 
number,  the  multiplier  thence  deduced  is  0;  and  the  quotient  10. 


'  This  had  not  been  previously  proposed :  probably  from  defect  of  the  manuscript. 
»  Sic. 


Sect.  V.    EQUATION  INVOLVING  SEVERAL  UNKNOWN.  355 

•    The  like  process  is  to  be  followed,  [for  deducing  the  elapsed  time]  from 
the  sum  of  residues  of  degrees  and  number  of  [elapsed]  days. 

Next,  the  number  of  days  with  past  seconds  is  [given]  twenty-two :  what 
is  in  this  instance  the  number  of  elapsed  days?^  Here  the  number  of  days,  is 
put  ya  1.  Whence,  as  before,  the  residue  of  minutes,  ya  108000 
cfl!  295*9200  Wi  246600  pi8Q20  lo  137.  This,  multiplied  by  sixty,  lessened 
by  subtraction  of  residue  of  seconds  equal  to  haritaca,  and  divided  by  the 
divisor,  the  quotient  is  seconds;  which,  added  to  the  number  of  days,  is 
equal  to  the  proposed  twenty-two.  Subtraction  being  made  on  the  two  sides 
of  equation  reduced  to  a  like  denominator,  the  value  o^ ydvat-tdvat  comes  out 
ca   177552000    ni   14796000    pi  493200    lo  8220     ha  1     ru  3014.     Here, 

ya  6480137 
substituting  with  four  for  n'llaca,  with  eleven  for  pitaca,  with  twenty-three  for 
lohitaca,  with  ninety-six  for  haritaca,  and  adding  the  values  so  raised  to  the 
absolute  number,  the  additive  becomes  64801370.  Whence,  as  before,  the 
multiplier  is  found  0;  and  the  quotient,  or  value  of  ydvat-tdvat,  10.  It  is 
the  number  of  [elapsed]  days.  Subtracting  this  from  twenty-two,  the  re- 
mainder is  the  [past]  seconds,  12. 

A  similar  process  is  to  be  followed  [for  the  elapsed  time]  from  the  sum  of 
residue  of  seconds  and  number  of  days. 

Example :  If  the  elapsed  [portion  of  the]  cycle,  added  to  the  past  exceed- 
ing months,  be  equal  to  three  thousand,  one  hundred  and  thirty-two,  tell  the 
elapsed  [portion  of  the]  cycle. 

Elapsed  [part  of  the]  cycle  ya  1 .  Multiplied  by  the  number  of  exceeding 
months  in  a  yuga  in  least  terms,  and  divided  by  the  solar  days  in  a  yiiga  also 
in  least  terms,  the  result  is  ya  \.     From  this  subtracting  the  residue  of  ex- 

7800 
ceeding    months,    ca    1,   the   remainder   is  [complete]   exceeding    months, 
ya  \    ca  \.     Adding  to  this  the  elapsed  [time  of  the]  cycle,  {ya  1,)  it  becomes 

1800 
t/a  1801    ca  \;  and  is  equal  to  3132.     Subtraction  being  made  on  the  two 

1800 
sides  of  equation  reduced  to  a  like  denominator,  the  multiplier  comes  out 

'  The  preceding  examples  not  being  specifically  proposed,  like  this  instance,  and  the  example  of 
minutes  and  their  residue  being  omitted,  the  manuscript  may  be  concluded  to  be  deficient. 

Z  Z  2 


356 


BRAHMEGUPTA. 


Chapter  XVIII. 


970;  and  the  quotient,  3130.  This  is  the  elapsed  [portion  of  the]  yuga. 
Subtracting  it  from  three  thousand,  two  hundred  and  thirty-two,  the  re- 
mainder is  the  number  of  past  exceeding  months,  2. 

In  Hke  manner,  find  severally  the  elapsed  [time  of  the]  cycle  from  elapsed 
time  added  to  residue  of  exceeding  months,  and  to  the  sum  of  the  past  ex- 
ceeding months  and  their  residue,  and  from  the  sum  of  [complete]  exceeding 
months  and  their  residue.  Four  other  problems  are  likewise  to  be  under- 
stood for  finding  elapsed  time  from  the  difference  between  this  and  the 
complete  exceeding  months,  and  so  forth. 

Example:  If  the  elapsed  [portion  of  a]  \imaT  yuga,  added  to  the  past  [de- 
ficient] days,  be  equal  to  one  thousand,  nine  hundred  and  eighty-two,  tell  me 
the  elapsed  lunar  time. 

Number  of  lunar  days,  ya  1.  Multiplied  hy  fewer  days  in  least  terms, 
and  divided  by  lunar  days  also  in  least  terms,  the  result  is  ya  7-     Subtracting 

555 
the  residue  oi facer  days,  for  which  put  culaca  1,  the  remainder  is  the  num- 
ber oi  fewer  days  complete,  ya7   ca\.     This,  added  to  the  numljer  of  lunar 

'555 
days,  ya  562    ca  1,  is  equal  to  one  thousand,  nine  hundred  and  eighty- two 

T5 
(1982).     Subtraction  being  made  on  the  two  sides  of  equation  reduced  to 
like  denominators,  the  multiplier,  or  value  of  calaca,  is  found  386;  it  is  the 
residue  o^fciver  days.     The  quotient,  or  value  of  ydvat-tavat,  is  1958.     It  is 
the  number  of  [elapsed]  lunar  days. 

In  like  manner  other  problems  are  to  be  understood. 

56.  Question  21.  He,  who  tells  the  number  of  [elapsed]  days,  from  the 
residue  of  minutes  added  to  the  residue  of  degrees  of  the  luminary,'  on  a 
Wednesday*  [or  any  given  day],  or  from  their  difference,  is  a  pcison  ac- 
quainted with  the  pulverizer. 


*  Bh&nu,  luminary,  applied  especially  to  the  sun  ;  but  here  apparently  intending  any  planet. 
See  the  following  problems,  and  the  commentator's  remarks  on  Question  25. 

*  In  this  and  several  following  instances,  a  day  is  specified  ;  but  no  notice  of  this  condition  is 
taken  in  the  example  and  its  solution,  until  Question  23. 


Sect.  V.     EQUATION  INVOLVING  SEVERAL  UNKOWN.         357 

Example :  Seeing  the  residue  of  degrees  of  the  moon,'  with  the  residue  of 
minutes  added  thereto,  equal  to  five  hundred  and  thirty-six;  or  with  that 
subtracted  from  it,  equal  to  three  hundred  and  forty-four:  tell  the  number 
of  days. 

Here  the  number  of  days  is  put  ya  1.  This,  multiplied  by  the  revolutions 
of  the  sun  in  least  terms,  and  divided  by  the  divisor,  is  ya  3.     Subtracting 

1096 
from  the  number  of  days  taken  into  the  revolutions,  the  divisor  taken  into 
the  quotient^  represented  by  cdlaca,  the  remainder  is  residue  of  degrees, 
ya  3  ca  IO96.  Hence,  as  before,  the  residue  of  degrees  is  found  ya  1080 
cfl  394560  wf  32880  pi  1096.  This  is  reserved;  and  multiplying  it  by 
sixty,  dividing  by  the  divisor,  subtracting  the  divisor  taken  into  the  quotient* 
represented  by  lohitaca,  the  remainder  is  the  residue  of  degrees,  ya  64800 
ca  £3673600  ni  1972800  pi  65760  lo  1096.  Thus  the  sum  of  these  resi- 
dues of  degrecsand  minutes  is  ya  65880  ca  24068160  ni  2005680  pi  66^56 
lo  1096.  It  is  equal  to  536.  Subtraction  being  made,  the  value  oi' nilaca  is 
assumed,  ru  1;  that  of  pitaca,  10;  of  lohitaca,  24;  and  multiplying  the 
[coefficients  of]  those  by  their  values,  [as  assumed,]  and  adding  the  products 
to  absolute  number,  the  amount  of  the  absolute  number  becomes  2701080. 
Whence,  as  before,  the  multiplier  is  found  0 ;  and  the  quotient,  or  number  of 
days,  4 1 . 

The  difference  between  the  residues  of  degrees  and  of  minutes  is  i/a  63720 
Cfl  23279040  mH 939920  /><  64664  lo  1096.  It  is  equal  to  344.  Subtrac- 
tion being  made,  and  putting  the  same  values  for  nilaca  and  the  rest,  the 
multiplier  comes  out,  as  before,  0;  and  the  quotient,  or  value  of  ydvat- 
tdvat,  41.     It  is  the  number  of  days. 

Or  what  occasion  is  there  for  this  trouble  ?  Putting  y&vat-tdvat  for  the  re- 
sidue of  degrees,  and  multiplying  by  sixty,  divide  by  the  divisor.  Subtrac- 
ting from  it  the  divisor  taken  into  the  quotient'  represented  by  cdlaca,  the 
.  remainder  is  residue  of  minutes.  Then  making;  the  sum  of  residues  of  mi- 
nutes  and  degrees  equal  to  the  proposed  sum,  and,  equal  subtraction  being 
made,  the  value  of  ydvat-tdvat,  which  comes  out,  is  the  residue  of  degrees ; 
from  which,  as  before,  the  number  of  [elapsed]  days  is  to  be  inferred. 

Or  else,  finding  the  residue  of  degrees,  and  that  of  minutes,  as  arising  for 

'  So  the  original.     But  the  example  is  wrought  as  an  instance  of  the  sun. 
*  Exclusive  of  the  fractional  residue. 


858  BRAHMEGUPTA.  Chafter  XVIII. 

one  day,  and  taking  their  sum  and  their  difference,  the  number  of  [elapsed] 
days  is  to  be  found  by  the  constant  pulverizer  thence  deduced. 
In  like  manner  [the  modes  of  solution]  are  manifold. 

57.  Question  22.  When  is  the  residue  of  degrees  of  the  sun,  with  three 
added,  equal  to  the  residue  of  minutes,  on  a  Wednesday?  or  with  six,  seven, 
or  eight,  subtracted?  Solving  [the  problem]  within  a  year  [the  proficient  is] 
a  mathematician. 

Here  sun  is  indefinite;  and  the  question  extends  therefore  to  any  given 
planet.  In  this  place  an  instance  of  the  moon  is  exhibited.  It  is  as  follows. 
Value  of  the  number  of  days,  ya  \.  Whence  the  residue  of  degrees  of  the 
moon,  ya  1800  cfl  49320  w«  4110  pi  137.  So  the  residue  of  minutes  is 
this,  j/«  108000  ca  2959200  m' 346600  pi  82Q0  lo  137.  Here  the jesidue 
of  degrees,  with  three  added,  is  equal  to  the  residue  of  minutes.  Subtrac- 
tion being  made  on  both  sides,  and  with  two  put  for  nilaca,  thirteen  for 
pitaca,  and  thirty-four  for  lohitaca,  the  multiplier  is  brought  out,  value  of 
cdlaca,  1 ;  and  the  quotient,  value  of  ydvat-tdvat,  5S.  The  value  of  cdlaca 
is  the  complete  revolutions ;  that  oi nilaca,  the  past  signs;  that  oi pitaca,  the 
degrees ;  and  that  of  lohitaca,  the  minutes. 

In  like  manner,  making  the  residue  of  degrees  less  six,  or  that  residue  less 
seven,  or  the  same  less  eight,  equal  to  the  residue  of  minutes,  the  number  of 
[elapsed]  days  is  to  be  found,  as  before. 

58.  Question  23.  When  is  the  residue  of  degrees  of  the  sun  equal  to  the 
[complete]  degrees ;  or  the  residue  of  minutes,  to  the  minutes,  on  a  given 
day?  Solving  [this  problem]  within  a  year  [the  proficient  is]  a  mathema- 
tician. 

Here  also  sun  is  indefinite,  and  intends  any  planet.  Therefore  the  residue 
of  degrees  of  the  moon  is  taken,  ya  1800  ca  49320  7ii  4110  pi  137.  This 
is  equal  to  the  complete  degrees,  the  value  of  which  is  represented  by  pitaca. 
Subtraction  being  made,  and  with  ten  put  for  7iilaca,  and  ten  for  pitaca,  the 
multiplier  comes  out  1,  and  the  quotient  51.  This  is  the  number  of  [elapsed] 
days. 

With  this  number  of  days,  the  residue  of  degrees  of  the  moon  is  equal  to 
the  complete  degrees. 

In  the  very  same  manner,  residue  of  minutes  of  the  moon,  ya  108000 


Sect.  V.    EQUATION  INVOLVING  SEVERAL  UNKNOWN.     359 

ca  2959200  n'l  246600  p'l  8220  lo  IsV-  This  is  equal  to  the  complete 
minutes,  the  value  of  which  is  represented  by  lohitaca.  Subtraction  being 
made  on  the  two  sides  of  the  equation,  and  with  nine  for  nilaca,  eleven  for 
p'ltaca,  and  ten  for  lohitaca,  the  multiplier  comes  out  4;  and  the  quotient  the 
value  of  the  number  of  days,  131.  To  find  for  the  given  day,  the  given 
multiple  of  the  divisor  is  to  be  added. 

Or  what  occasion  is  there  for  the  trouble  of  supposing  [values  of]  colours? 
Vutim^  ydvat-tdvat  for  the  residue  of  degrees;  and  from  that  multiplied  by 
thirty  and  divided  by  the  divisor,  subtracting  tlie  quotient*  represented  by 
c&laca,  taken  into  its  divisor,  the  remainder  is  residue  of  degrees.  Making 
it  equal  to  degrees,  equal  subtraction  is  then  to  be  made;  whence  the  value 
of  ydvat-tdvat  is  brought  out.  It  is  the  residue  of  degrees;  from  which,  as 
before,  the  number  of  [elapsed]  days  is  to  be  deduced. 

59.  Question  24.  Residue  oi fewer  days,  with  a  given  quantity  added  or 
subtracted,  or  residue  of  Tfiore  months,  with  the  like,  is  equal  to  fewer  days; 
or  to  more  months.  Solving  [this  problem]  within  a  year  [the  proficient  is]  a 
mathematician. 

It  is  as  follows.  Elapsed  [portion  of  the]  yuga  1 .  Multiplied  by  exceed- 
ing months  in  least  terms,  and  divided  by  solar  days  also  in  least  terms,  and 
the  quotient  lessened  by  subtraction  of  cdlaca  representing  the  complete  ex- 
ceeding months,  the  result  is^a  1  ca  1080.  It  is  the  residue  of  exceeding 
months,  and  is  equal  to  cdlaca.  Whence  the  multiplier  comes  out  1,  and  the 
quotient  1081.     This  is  the  elapsed  [portion  of  the]  yuga. 

Or  equal  to  cdlaca  with  five  added.  The  quotient,  which  is  the  elapsed 
yuga,  comes  out  1086. 

In  the  question  relating  to  fewer  days,  the  elapsed  [portion  of  the]  yuga  is 
ya  1.  This,  multiplied  by  deficient  days  in  least  terms,  and  divided  by  lunar 
days,  and  lessened  by  subtraction  of  the  divisor  taken  into  cdlaca  put  for  the 
quotient,'  the  result  is  ya  7  ca  555.  This  is  equal  to  cdlaca.  The  multi- 
plier thus  comes  out  7;  and  the  quotient,  the  value  o£  ydvat-tdvat,  556.  It 
is  the  elapsed  lunar  yuga. 

Or  equal  to  cdlaca,  with  three  added ;  the  multiplier  comes  out  6 ;  and 
the  quotient,  or  elapsed  yuga,  477- 

'  Exclusive  of  the  fractional  residue. 


S60 


BRAHMEGUPTA. 


Chapter  XVIII. 


Or  equal  to  c&laca,  less  two,  the  multiplier  is  found  3;  and  the  quotient, 
or  elapsed  _y«5'fl,  238. 

60.  Question  25.  The  sun's'  divisor  in  least  terms,  multiplied  by  seventy, 
and  lessened  by  the  residue  of  degrees,*  is  exactly  divisible  by  a  myriad. 
Solving  [this  problem]  within  a  year  [the  proficient  is]  a  mathematician. 

Here  the  sun's  divisor  in  least  terms  is  1096.  This,  multiplied  by  seventy, 
is  76720.  "  Lessened  by  the  residue  of  degrees :"  the  value  of  residue  of  de- 
grees is  put  ya  1 :  less  that,  is  ya  \  ru  76720.  This  divided  by  a  myriad  is 
exact.     Statement  3/fl  i    ru  76720.     The  value  of  the  quotient  is  put  cdlaca  1. 

10000 
Making  this  taken  into  the  divisor  equal  to  the  dividend,  and  equal  subtrac- 
tion being  then  made,  the  rpsiilt  is  ca  iOOOO    ru  76720.     The  pulverizer 

comes  out  1.  It  is  the  multiplier,  and  the  value  of  y&vat-tavat  is  76720. 
This  is  the  residue  of  degrees :  whence  the  number  of  [elapsed]  days  is  de- 
duced, 95. 

Abridging  by  eighty,  it  is  found  by  means  of  the  constant  pulverizer. 

This  is  to  be  variously  illustrated  by  example. 


'  Sun  (bh&nu)  is  here  indefinite  ;  and  intends  planets  generally. 

I  This  is  indefinite.    Residue  of  revolutions,  and  the  like,  is  intended. 


Com. 
Com. 


(     361     ) 


SECTION  vr. 


EQUATION  INVOLVING  A  FACTUM. 

61.  Rule  :  §  36.  The  [product  of]  multiplication  of  the  factum  and  abso- 
lute number,  added  to  the  product  of  the  [coefficients  of  the]  unknown,  is 
divided  by  an  arbitrarily  assumed  quantity.  Of  the  arbitrary  divisor  and 
the  quotient,  whichever  is  greatest  is  to  be  added  to  the  least  [coefficient], 
and  the  least  to  the  greatest.  The  two  [sums]  divided  by  the  [coefficient 
of  the]  factum  are  reversed. 

62.  Question  26.  From  the  product  of  signs  and  degrees  of  the  sun, 
subtracting  thrice  the  signs  and  four  times  the  degrees,  and  seeuig  ninety 
[for  the  remainder,  find  the  place  of]  the  sun.  Solving  [this  problem] 
within  a  year  [the  proficient  is]  a  mathematician. 

Signs  of  the  sun^^a  1.  Degrees  ca  1.  Their  product  ya.cahh  1.  Sub- 
tracting from  this  thrice  the  signs  and  four  times  the  degrees,  the  result  is 
ya.ca  bh  \  ya  h  ca  4.  It  is  equal  to  ninety.  Subtraction  being  made,  see 
the  result:  ya  3  ca  4>  ru  30      Here  the  multiplication  of  the  [coefficient  of 

ya.ca  bh  1 
the]  factum  and  absolute  number  is  90.     With  the  product  [of  the  coeffi- 


'  In  an  example,  in  which  a  factum  arises  from  the  multiplication  of  two  or  of  more  colours, 
having  made  two  sides  equal,  and  taking  the  factum  from  one  side,  subtract  the  absolute  number 
together  with  the  [single]  colours  from  the  other.     The  equation  so  standing,  the  rule  takes  effect. 

TTie  multiplication  of  absolute  number  by  the  coefficient  of  the  factum  is  termed  multiplication 
of  the  factum  and  absolute  number.  That,  together  with  the  product  of  the  two  unknown,  is  to  be 
divided  by  an  arbitrary  quantity.  Between  the  arbitrary  divisor  and  quotient,  the  greater  is  to  be 
added  to  the  less  coefficient,  and  the  less  to  the  greater  coefficient.  The  two  sums,  divided  by  the 
coefficient  of  the  factum,  being  reversed,  arc  values  of  the  colours.  The  meaning  is,  that,  to  which 
the  coefficient  o{ y/nat-tdxat  is  added,  is  the  value  of  cdlaca;  and  that,  to  which  the  coefficient  of 
cdlaca  is  added,  is  the  value  oi ydvat-tixat. 

But,  when  a  factum  consisting  of  many  colours  occurs,  then  reserving  two,  and  assuming  arbi- 
trary values  for  the  rest  of  the  colours,  multiply  by  them  the  factum  of  the  two  reserved  colours. 
Thence  the  rest  is  to  be  done  as  above  directed.  Com. 

3  A 


362  BRAHMEGUPTA.  Chapter  XVIII. 

cients]  of  the  unknown,  namely  12,  added,  it  becomes  102.  Divided  by  the 
assumed  number  17,  the  quotient  is  6.  It  is  "  least;"  and  to  it  is  added  the 
greater  coefficient  4,  making  10.  The  "  greater"  is  17;  to  which  the  least 
coefficient  3  is  added,  making  20.  These,  divided  by  the  [coefficient  of  the] 
factum  [viz.  1],  become  values  of  yAvat-tavat  and  calaca,  10  and  20.  Signs 
of  the  sun  10;  degrees  20.  Its  degrees  [320],  multiplied  by  the  divisor  in 
least  terms,  namely  IO96,  (making  350720,)  and  divided  by  the  degrees  in  a 
revolution  [360],  yield  as  product  the  residue  of  revolutions.  With  unity 
added,  that  residue  is  975.  Whence,  as  before  directed,  the  number  of 
[elapsed]  days  is  to  be  found,  325. 

63 — 64.  Rule:*  §  37 — 38.  With  the  exception  of  one  selected  colour,  put 
arbitrary  values  for  the  rest  of  those,  the  product  of  which  is  the  factum. 
The  sum  of  the  products  of  the  [coefficients  of]  colours  by  those  [assumed 
values]  is  absolute  number.  The  product  of  the  assumed  values  of  colours 
and  [coefficient  of]  the  factum  is  coefficient-  of  the  selected  colour.  Thus 
the  solution  is  effiscted  without  an  equation  of  the  factum.  What  occasion 
then  is  there  for  it? 

Here  the  foregoing  example  (Qu.  26)  serves.     As  before,  having  done  as 

directed,  the  two  sides  of  equation  become  ya  3  c«  4  ru  90      Reserving 

ya  .ca  bh  1 

ycivat-tdvat,  Avhich  is  selected,  an  arbitrary  value  is  put  for  calaca  20.     The 

coefficient  of  calaca,  multiplied  by  that,  is  80 ;  added  to  absolute  number, 

this  becomes  570.     Now  the  coefficient  of  the  factum  (1),   multiplied  by 

calaca,  becomes  coefficient  of  ydvat-tdvat,  20.     Statement  of  the  two  sides  of 

equation  thus  prepared,  ya  3  ru  170     Proceeding  by  a  former  rule  (§  32), 

3/a20 

the  value  of  ydvat-tdvat  comes  out  10. 

'  Having  thus  set  forth  the  [solution  of  a]  factum  according  to  the  doctrine  of  others,  the  author 
now  delivers  his  own  method  with  a  censure  on  the  other.  Com. 

*  Sanc'hyii,  number:  meaning  coefficient  usually  expressed  by  anca,  figure. 


I 


(    363    ) 
SECTION  VII. 


SQUARE  AFFECTED  BY  COEFFICIENT. 

65 — 66.  Rule:  §  39 — 40.  A  root  [is  set  down]  two-fold:  and  [another, 
deduced]  from  the  assumed  square  multiplied  by  the  multiplier,  and  in- 
creased or  diminished  by  a  quantity  assumed.  The  product  of  the  first 
[pair],  taken  into  the  multiplier,  with  the  product  of  the  last  [pair]  added,  is 
a  "last"  root.'  The  sum  of  the  products  of  oblique  multiplication  is  a  "  first" 
root.  The  additive  is  the  product  of  the  like  additive  or  subtractive  quan- 
tities. The  roots  [so  found],  divided  by  the  [original]  additive  or  subtractive 
quantity,  are  [roots  answering]  for  additive  unity.* 

'  The  terras  familiarly  used  for  the  practice  of  solution  of  problems  under  this  head  are  here 
explained  :  viz. 

Canisht'ha  or  6dya  (pada  or  mula)  least  or  first  root ;  that  quantity,  of  which  the  square  multi- 
plied by  the  given  multiplicator  and  having  the  given  addend  added,  or  subtrahend  subtracted,  is 
capable  of  affording  an  exact  square  root. 

Jyeshi'ha  or  antya  (pada  or  mula)  greatest  or  last  root :  the  square-root  which  is  extracted  from 
the  quantity  so  operated  upon. 

Pracrni,  the  multiplier  [the  coefficient  of  the  first  square]. 

Cshepa,  cshiptic6,  chipti,  additive,  or  addend  :  the  quantity  to  be  added  to  the  square  of  the  least 
root  multiplied  by  the  multiplicator,  to  render  it  capable  of  yielding  an  exact  square-root. 

Svd'haca,  subtractive,  or  subtrahend  :  the  quantity  to  be  subtracted  for  the  like  purpose. 

Udvartaca,  the  quantity  assumed  for  the  purpose  of  the  operation. 

j^pararla,  abridger,  common  measure ;  the  divisor,  which  is  assumed  for  both  or  either  of  the 
<|uantities. 

Vqjru-bad'ha,  forked  or  oblique  [that  is,  cross]  multiplication.     See  Vij.-gan.  §  77-  Com. 

*  The  root  of  any  square  quantity  is  to  be  set  down  twice  ;  that  is,  being  repeated,  the  second 
is  to  be  put  under  the  first.  These  two  are  "  least"  roots.  Then  multiplying  by  the  multiplicator 
the  square  of  the  "  least"  root,  consider  what  quantity,  added W  subtracted,  will  render  it  capable  of 
yielding  an  exact  root.  The  quantity,  of  which  the  addition  effects  that,  is  "  additive."  That, 
of  which  the  subtraction  effects  it,  is  "  subtractive."  So  doing,  the  root,  which  is  afforded,  is 
"  greatest"  root.  This  also  is  to  be  set  down  in  two  places,  in  front  of  the  "  least"  roots.  Being  so 
arranged,  the  product  of  the  two  least  roots  multiplied  by  the  multiplicator,  with  the  product 
of  the  two  greatest,  is  a  "  greatest"  root.  That  is  to  say,  it  is  so  by  composition.  The  product 
of  multiplication  crosswise,  or  obliquely,  like  forked  or  crossing  lightning,  is  product  of  oblique 
multiplication.     That  is,  the  least  and  greatest  roots  are  twice  multiplied   cornerwise.     The 

3  A  2 


364  BRAHMEGUPTA.  Chapter  XVIII. 

61.  Question  87.  Making  the  square  of  the  residue  of  signs  and  mi- 
nutes on  a  Wednesday,  multiplied  by  ninety-two  and  eighty-three  respec- 
tively, with  one  added  to  the  product,  [afford,  in  each  instance]  an  exact 
square,  [a  person  solving  this  problem]  within  a  year  [is]  a  mathematician. 

Here  the  assumed  square  is  put  1 .     Its  root  is  "  least"  root.     Set  down 

twice,  L  1      Again  the  same  square,  multiplied  by  ninety-two,  and  having 
L  1 

eight  added  [to  make  it  yield  a  square-root],  amounts  to  100:  the  root  of 
which  is  "  greatest,"  10.     Statement  of  them  in  order  L  1  G  10  A  8     Then, 

L  1  G  10  A8 
pjoceeding  by  the  rule  (the  product  of  the  first  taken  into  the  multiplier,  &c. 
§  39 — 40)  the  "  least"  and  "  greatest"  roots  for  additive  sixty-four  are  found 
L  20  G  192  A  64.  By  the  concluding  part  of  the  rule  (§  40)  the  "  least"  and 
"  greatest"  roots  for  additive  unity  come  out  L  ^  G  24  A  1 .  Again,  from  this, 
by  the  combination  of  like  ones,  other  least  and  greatest  roots  are  brought  out 
L  120  G  1 151  A  1.  Here  the  "  least"  root  is  residue  of  degrees.  Whence, 
as  before,  the  number  of  [elapsed]  days  is  deduced,  Qs. 

In  the  second  example,  the  square  assumed  is  1.  Its  square-root  is 
"  least"  root,  ].  From  the  assumed  square,  multiplied  by  eighty-three,  and 
lessened  by  subtraction  of  two,  the  square-root  extracted  is  "  greatest,"  9. 
Proceeding  by  the  rule  (§  ^'^■,  the  "  greatest"  root  comes  out,  164 ;  and  by  the 
sequel  of  it  (§40),  the  "  least"  root,  18;  and  these,  divided  by  the  sub- 
tractive,  namely  2,  become  roots  for  additive  unity,  L  9  G  82  A 1 .  The 
"  least"  is  residue  of  minutes:  whence,  as  before,  the  number  of  [elapsed]  days 
is  found,  22. 

68.  Rule:  §41.'  Putting  severally  the  roots  for  additive  unity  under  roots 
for  the  given  additive  or  subtractive,  "  last"  and  "  first"  roots  [thence  deduced 
by  composition]  serve  for  the  given  additive  or  subtract! ve." 

sum  of  these  two  products  is  a  "  least"  root  by  composition.  But  the  additive  by  composition 
amounts  to  the  product  of  the  two  lii<e  additives  or  subtractives.  Then  the  least  and  greatest  roots, 
so  derived  from  composition,  being  divided  by  the  number  of  the  [original]  additive,  or  by  that  of 
the  subtractive,  are  roots  serving  when  unity  is  the  additive.  Com. 

■  When  the  additive  is  many  [i.  e.  more  than  unity].  Com. 

*  Under  least  and  greatest  roots,  which  serve  for  the  given  additive  or  subtractive,  are  to  be 
placed  least  and  greatest  roots  serving  for  additive  unity;  then  the  roots,  which  are  found  by  the 
foregoing  rule  (§  39—40),  arc  roots  which  also  serve  for  the  same  given  additive  or  subtractive. 

Com. 


Sect.  VII.      SQUARE  AFFECTED  BY  COEFFICIENT.       '       365 
An  example  will  be  given  further  on.' 

69.  Rule:  §  42.  When  the  additive  is  four,  the  square  of  the  last  root,  less 
three,  being  halved  and  multiplied  by  the  last,  is  a  last  root ;  and  the  square 
of  the  last  root,  less  one,  being  divided  by  two  and  multiplied  by  the  first,  is 
a  first  root,  [for  additive  unity].* 

70.  Question  28.  jNIaking  the  square  of  the  residue  of  revolutions  or  the 
like,  multiplied  by  three  and  having  nine  hundred  added,  an  exact  sc[uare  ;  or 
having  eight  hundred  subtracted;  [a  persou  solving  this  problem]  within  a 
year  [is]  a  mathematician. 

Here  the  assumed  square  is  put  4.  Its  root  is  a  least  root  2.  Its  square  4, 
multiplied  by  the  coefficient  3,  is  12  ;  and  with  4  added,  16.  Its  square- 
root  is  a  greatest  root,  4.  L  £,  G  4.  From  this  are  to  be  found  roots  for 
additive  unity.  Here  the  last  root  is  4  :  its  square  ]6;  less  three,  13 ;  halved, 
J^;  multiplied  by  last  root,  26;  this  is  a  last  root  for  additive  unity.  Again, 
square  of  the  last  root,  16;  less  one,  15;  divided  by  two,  ^;  multiphed  by 
the  first  root,  gives  a  first  root,  15.  The  meaning  of  the  rest  of  the  question 
is  shown  [farther  on].' 

71.  Rule:*  §  43.  When  four  is  subtract! ve,  the  square  of  the  last  root  is 
twice  set  down,  having  three  added  in  one  instance  and  one  in  the  other : 

•  See  Qu.  32. 

*  Under  the  rule  "  A  root  is  set  down  twofold,"  &c.  (§  39),  if  four  be  the  additive,  then  the 
[original]  last  root  being  squared,  and  lessened  by  three,  the  half  of  the  remainder,  multiplied  by  the 
last  root,  is  a  last  root,  answering,  however,  to  additive  unity.  Again,  the  square  of  the  [original] 
t&st  root,  lessened  by  one,  divided  by  two,  and  multiplied  by  least  root,  is  a  least  root,  the  additive 
being  unity.  Co.v. 

'  See  Qu.  32. 

♦  Rule  to  find  roots  answering  for  additive  unity,  from  roots  which  serve  when  four  is  subtractive. 

Com. 
Of  least  and  greatest  roots  serving  when  four  is  subtractive,  the  square  of"  last"  root  is  twice 
set  down,  having  three  added  in  the  one  instance,  and  one  added  in  the  other.  The  moiety  of  the 
product  of  those  reserved  quantities  is  also  to  be  twice  set  down,  having  one  subtracted  in  the  one 
instance,  and  as  it  stood  in  the  other.  That  which  is  diminished  by  one,  is  next  "  multiplied  by 
the  former  less  one;"  that  is  to  say,  multiplied  by  the  square  of  "  last"  root  [having  three  added] 
less  one.  So  doing,  the  result  is  "  greatest"  root  for  unity  additive.  The  moiety  of  the  product, 
which  was  set  down  as  it  stood,  being  multiplied  by  the  product  of"  least"  and  "  greatest"  roots,  is 
"  least"  root  for  additive  unity.  Com. 


366  BRAHMEGUPTA.  Cuapter  XVIII. 

half  the  product  of  these  sums  is  set  apart,  and  the  same  less  one.  This, 
multiplied  by  tlie  former  less  one,  is  "  last"  root.  The  other,  multiplied  by 
the  product  of  the  roots,  is  "  first"  root  answering  to  that  "  last.' 

72.  Question  29.  The  square  of  residue  of  exceeding  months,  multi- 
plied by  thirteen,  and  having  three  lumdrcd  added,  or  the  cube  of  three  sub- 
tracted, affords  an  exact  square.  A  person  solving  [this  problem]  is  a 
mathematician. 

Here  the  assumed  square  is  put  1.  Its  root  is  1:  it  is  a  least  root.  The 
square  of  this  multiplied  by  thirteen,  and  lessened  by  four,  is  9-  Root  of  the 
remainder  3 :  a  greatest  root  is  thus  found.  From  these  least  and  greatest 
roots,  L  1  G  3,  roots  are  to  be  found  for  additive  unit\-.  In  this  case,  the 
last  root  is  3:  its  square  twice,  9  and  9;  with  three  and  one  added,  12  and 
10.*  Again,  half  the  product  of  those  reserved  quantities,  (>0:  multiplied  by 
the  product  of  the  least  and  greatest  roots,  namely,  3,  makes  180.  The  least 
root  is  thus  found.  The  purport  of  the  rest  of  the  question  is  shown  further 
on.* 

73.  Rule:'  §  44.  If  a  square  be  the  multiplier,  the  additive  [or  subtractive] 
divided  by  any  [assumed]  number,  and  having  it  added  and  subtracted,  and 
being  then  [in  both  instances]  halved;  the  first  is  a  "  last"  root;  and  the  last, 
divided  by  the  square-root  of  the  multiplier,  is  a  "  first."* 

74.  Question  30.  The  square  of  a  residue  of  revolutions,  or  the  like, 
multiplied  by  four,  and  having  sixty-five  added,  or  having  sixty  subtracted, 
is  a  square.  Solving  [this  problem]  within  a  year  [the  proficient  is]  a  mathe- 
matician. 

•  Something   is   here    wanting    n    the    MS.    /"igx  10— 1  \  x(3^+3—])=a9x  11=649= 

(180^x13)4-1. 
'  See  below. 
^  To  find  roots,  when  the  coefficient  is  an  exact  square.  Com. 

♦  When  a  square  number  is  the  multiplier,  the  additive  must  be  divided  by  any  number  arbitra- 
rily put.  The  quotient  must  then  have  the  same  assumed  number  added  in  one  place  and  sub- 
tracted in  another.      Having  thus  formed  two  terms,  halve  them  both.    The  first  of  these  moieties 

'    is  "  greatest'  root.   The  second,  divided  by  the  square-root  of  the  multiplier,  is  "  least"  root.  Com. 
In  one  case,  however,  the  first  of  the  moieties,  divided  by  the  square-root  of  the  coelTicient,  is 
"  least"  root,  and  the  second  is"  greatest"  root ;  as  is  lemarked  under  the  following  example. 


Section  VII.     SQUARE  AFFECTED  BY  COEFFICIENT.  367 

Statement:  IVIultipHcr  4.  Additive  65.  Here  the  additive  divided  by  an 
arbitrarily  assumed  number,  5,  is  13.  This,  increased  and  lessened  l)y  the 
assumed  number,  becomes  1 8  and  8.  The  half  of  the  first  of  these  is  "  greatest" 
root,  9.  The  moiety  of  the  second,  divided  by  the  root  of  the  multiplier,  2, 
gives  the  "  least"  root,  S. 

Statement  of  the  second  example :  IMultiplier  4.  Additive  6'0.  "  Additive" 
in  the  rule  (§  44)  is  indefinite  and  intends  subtractive  also.  Here  let  the. 
assumed  number  be  2.  By  this,  the  subtractive,  namely,  60,  being  divided, 
makes  30.  This,  with  the  assumed  number  added  and  subtracted,  gives  32 
and  28:  the  moieties  of  which  are  16  and  14.  The  text  expresses  "  the  fii-st 
is  a  last  root,"(§  44):  but  that  is  a  part  only  of  the  rule.  The  second  then  is 
"  greatest"  root,  14.  The  first,  divided  by  the  square-root  of  the  multiplier,  is 
the  "  least"  root,  8. 

75.  Rule :  §  45.  If  the  multiplier  be  [exactly]  divided  by  a  square,  the 
first  root  is  [to  be]  divided  by  the  square-root  of  the  divisor.* 

76.  Question  31.  The  square  of  a  residue  of  deficient  days,  being  mul- 
tiplied by  twelve,  and  having  a  hundred  added,  or  having  three  subtracted,  is 
a  square.  Solving  [this  problem]  within  a  year  [the  proficient  is]  a  mathe- 
matician. 

Here  multiplier  12,  divided  by  the  square  4,  yields  3.  Hence,  least  and 
greatest  roots  answering  to  additive  a  hundred  are  deduced,  10  and  20. 
The  least  root,  10,  being  divided  by  the  square-root  of  that  square,  gives  the 
"  least"  root  for  the  multiplier  twelve,  viz.  5.  Thence,  as  before,  the  elapsed 
[portion  ofj  yuga  is  793.     The  "  greatest"  root  is  the  same,  20. 

In  the  second  example,  the  least  and  greatest  roots,  as  found  for  a  multi- 
plier divided  by  the  square  number,  are  2  and  3;  for  subtractive  three. 
The  first,  divided  by  the  square-root  of  that  square,  is  the  "  least"  root,  1 ;  the 
"greatest"  is  the  same  3;  for  th«  nmltiplicr  twelve.  Here  the  "  least"  root 
is  the  residue  of  deficient  days. 

'  If  the  multiplier  can  be  abridged  by  a  square,  then  reducing  to  its  least  term,  let  roots  be  found 
as  before.  But  the  first  root  so  found  being  divided  by  the  square-root  of  the  abridging  divisor,  is 
"  least"  root.     The  "  greatest"  root  remains  the  same. 

But,  if  the  coefficient  be  multiplied  by  a  square  quantity,  it  of  course  follows,  that  the  first  root> 
multiplied  by  the  square-root  of  that  square,  is  the  "  least"  root.  Com. 


368  BRAHMEGUPTA.  Chapter  XVIIL 

Rule:  [45  completed.]  If  the  additive  Ije  exactly  divisible  by  a  square, 
the  roots  must  be  multiplied  by  the  square-root  of  the  divisor.' 

77.  Question  32.  The  square  of  residue  of  revolutions,  or  the  like, 
multiplied  by  three,  and  having  nine  hundred  added,  or  eight  hundred  sub- 
tracted, is  a  square.  Solving  [this  problem]  within  a  year  [the  proficient  is] 
a  mathematician. 

Statement:  Multipher  S.  Additive  900.  Here  the  additive  is  divided  by 
the  square  number  900;  and  the  quotient  is  1:  whence  the  "  least"  and 
"greatest"  roots  are  deduced,  1  and  2.  These,  multiplied  by  the  square-root 
of  the  abridging  divisor,  namely,  30,  become  the  "  least"  and  "  greatest"  roots 
for  the  additive  nine  hundred,  30  and  60. 

Statement  for  the  second  example:  Multipliers.  Subtractive  800.  Here 
the  subtractive,  being  divided  by  four  hundred,  becomes  2.  Whence  "  least" 
and  "  greatest"  roots  are  deduced,  1  and  1.  These,  multiplied  by  twent}',  are 
20  and  20,"  least"  and  "greatest"  roots  serving  for  subtractive  eight  hundred. 

In  any  instance,  where  the  additive  is  exactly  divisible  b}-  a  square,  the  least 
and  greatest  roots,  which  are  thence  deduced,  being  multiplied  by  the  square- 
root  of  the  abridging  divisor,  become  roots  adapted  to  that  additive  or  sub- 
tractive.  And  further,  by  composition  of  the  roots  so  found  for  the  given 
additive,  with  roots  serving  for  additive  unity,  other  roots  are  derived  for  the 
same  additive.      For  instance,  L  30    G  60    A  900     By  the  preceding  rules 

L   1     G   2    A     1 
(§39 — 40  and  41)  other  "least"  and  "greatest"  roots  are  here  found,   120 
and  210.     So  in  all  similar  cases. 

78.  Rule:  To  find  a  quantity  such,  that,  being  severally  multiplied  by 
two  multipliers,  and  having  unity  added  in  each  instance,  both  sums  may 
afford  square  roots:  §  46.     The  sum  of  the  multiplier,  being  multiplied  by 


'  If  the  additive  can  be  abridged  by  any  square,  devising  least  and  greatest  roots  as  before,  for  the 
abridged  additive,  both  being  then  multiplied  by  the  square-root  of  the  abridging  divisor  of  the  ad- 
ditive, become  adapted  to  their  proper  additive. 

Of  course,  if  the  additive  be  raised  by  multiplication  by  any  square  multiplier,  the  least  and 
greatest  roots,  wrhich  are  thence  deduced,  must  be  divided  by  the  square-root  of  the  additive's  mul- 
itiplier,  and  thus  become  least  and  greatest  roots  adapted  to  their  proper  additive.  Com. 


Section  VII.     SQUARE  AFFECTED  BY  COEFFICIENT.  369 

eight,  and  divided  by  the  square  of  their  difference,  is  the  quantity  [sought]. 
The  twomultipHers,  tripled  and  added  to  the  opposite,  and  divided  by  the 
difference,  are  the  roots.* 

79-  Question  33.  The  residue  of  seconds  of  the  moon,  severally  multi- 
plied by  seventeen,  and  by  thirteen,  and  having  one  added,  [becomes  in  both 
instances]  a  square.  Solving  [this  problem]  within  a  year  [the  proficient  is] 
a  mathematician. 

Here  the  multipliers  are  17  and  13.  Their  sum  30:  multiplied  by  eight, 
240.  Difference  of  the  multipliers  4:  its  square  l6.  Quotient  of  the  divi- 
sion, 15:  it  is  the  number  [sought];  and  it  is  the  residue  of  the  seconds  of 
the  moon. 

To  find  the  roots:  multipliers  17,  13;  multiplied  by  three,  51,  39:  added 
to  the  reciprocals,  56,  64.  Divided  by  the  difference  of  the  multipliers  4,  the. 
roots  come  out  14,  ]6. 

80.  Rule :  §  47-  A  square,  with  another  square  added  and  subtracted, 
being  multiplied  by  the  quotient  of  the  sum  of  that  sum  and  difference 
divided  by  the  square  of  half  their  difference,  produces  numbers,  of  which 
both  the  sum  and  difference  are  squares;  as  also  the  product  with  one  added 
to  it.* 

81.  Question  34.  The  residue  of  minutes  of  the  sun  on  Wednesday, 
having  the  residue  of  seconds  on  Thursday  added  and  subtracted,  yields  in 
both  instances  an  exact  square;  and  so  does  the  product  with  one  added.  A 
person  solving  [this  problem]  within  a  year  is  a  mathematician. 

Here  let  an  assumed  square  be  16;  with  another  square,  as  4,  added  and 


an 


a 


*  The  proposed  muhipliers  are  to  be  added   togetlier  :  and  the  sum,  being  multiplied  by  eight, 
r.d  divided  by  the  square  of  the  difference  of  these  multipliers,  is  the  quantity  [sought].     How  are 

the  roots  found  ?  The  author  proceeds  to  reply  :  multiplying  the  multipliers  seves-ally  by  three, 
idd  to  the  two  products  the  opposite  multiplier  respectively.  Then  dividing  by  the  difference  of 
the  multipliers,  the  quotients  are  the  roots.  Com. 

*  Some  squaie  of  an  arbitrary  number  is  to  be  set  down  ;  and  the  square  of  another  arbitrary 
number  is  to  be  added  in  one  place  and  subtracted  in  another.  The  sum  of  these  two  quantities  is 
divided  by  the  square  of  half  their  difference :  the  quotient  is  their  multiplier.  Multiplied  by  it, 
they  are  the  numbers  sought  :  of  which  if  the  sum  be  taken,  it  is  a  square  ;  if  the  difference,  it 
also  i$  square  ;  if  the  product  with  unity  added,  this  again  is  square.  Com. 

3  B 


-379.^  5RAHMEGUPTA,  Chapter  XVIII. 

subtracted,  20  and  12:  sum  of  these  32.  Divided  by  the  square  of  half  the 
difference  of  these  quantities,  namely  16,  the  quotient  is  their  muUipHcr,  2. 
MultipUed  by  it,  the  two  quantities  come  out  40,  24.  The  first  is  residue  of 
minutes  of  the  sun,  40.  Hence,  as  before,  the  number  of  [elapsed]  days  is 
deduced,  3385.  The  second  is  residue  of  seconds  of  the  sun,  24:  whence  the 
number  of  days,  27.  Adding  five  times  the  divisor,  5480,  the  number  of 
[elapsed]  days  on  Thursday  comes  out  5509.  So,  by  virtue  of  suppositions, 
manifold  answers  may  be  obtained. 

82.  Rule:  To  find  a  quantity,  such,  that  having  two  given  numbers 
added,  or  else  subtracted,  the  results  may  be  exact  squares :  §  48.  The  dif- 
ference of  the  numbers,  by  addition  or  subtraction  of  which  the  quantity  be- 
comes a  square,  is  divided  by  an  arbitrary  number  and  has  it  added  or  sub- 
tracted: the  square  of  half  the  result,  having  the  greater  number  added  or 
subtracted,  is  the  quantity  v  hich  answers  in  the  case  of  addition  or  sub- 
traction.* 

83.  Question  35.  IMaking  the  residue  of  minutes  of  the  sun  on  a  Wed- 
nesday, with  the  addition  of  twelve  and  of  sixty-three,  and  with  the  subtrac- 
tion of  sixty  and  of  eight,  an  exact  square ;  [the  proficient  solving  the  pro- 
blem] within  a  year  is  a  mathematician. 

Two  questions  are  here  proposed.  The  numbers,  which  are  to  be  added  to 
the  quantity,  are  separated,  12,  63.  Their  diiference,  51;  divided  by  an 
arbitrary  number,  as  3,  gives  17;  with  the  same  added,  since  addition  is  in 
question,  the  sum  is  20:  its  moiety,  10;  the  square  of  which  is  100.  The 
greater  of  the  two  additive  quantities  is  6^.     Subtracting  this,  the  result  is 


"  Of  the  two  quantities,  the  addition  of  which  makes  the  quantity  in  question  an  exact  square,  or 
the  subtraction  of  which  does  so,  the  difference  is  in  every  case  to  be  taken.  This  step  is  common 
to  both  methods.  Dividing  the  difference  then  by  an  arbitrary  number;  the  quotient  must  have 
added  to  it  the  same  arbitrary  number  ;  if  addition  were  given  by  the  question  :  but,  if  subtraction 
were  so,  the  same  quotient  must  have  the  arbitrary  number  subtracted.  Then  the  quantity  result- 
ing in  either  case  is  to  be  halved  ;  and  the  half,  to  be  squared.  [From  which  subtracting  the 
greater  number,  the  remainder  is  the  quantity  which  answers*]  if  the  condition  were  addition  : 
but,  if  it  were  subtraction,  the  square  of  the  moiety  appertaining  to  the  case  being  added  to  the 
greater  number,  the  sum  is  the  quantity  sougiit.  Com. 

*  Tbe  original  ii  deficient :  but  ma;  be  tbus  supplied  froia  compariaon  of  the  text,  and  of  the  eiample  as  wrought. 


Section  VII.     SQUARE  AFFECTED  BY  COEFFICIENT.  371 

the  quantity  sought,  Zl.  With  either  twelve  or  sixty-three  added,  it  is  an 
exact  square. 

In  the  example  of  subtraction;  the  two  numbers  which  are  to  be  sub- 
tracted to  make  a  square,  are  60,  8.  Their  difference,  divided  by  an  arbi- 
traiy  number,  namely  two,  yields  26 :  less  the  arbitrary  number,  leaves  24 : 
its  moiety  12;  the  square  of  which  is  144.  Here  the  greater  of  the  two 
subtractive  quantities  is  60.  This  added  to  the  square  is  204.  It  is  the 
quantity,  which  lessened  by  sixty,  affords  a  square  root ;  or  by  eight.  It  is 
the  residue  of  minutes  of  the  sun.  Hence,  as  before,  the  number  of  [elapsed] 
days  on  Wednesday,  is  to  be  deduced. 

In  Uke  manner,  by  virtue  of  suppositions,  manifold  answers  may  be  ob- 
tained. 

84.  Rule  :  §  49-  The  sum  of  the  numbers,  the  addition  and  subtraction  of 
which  makes  the  quantity  a  square,  being  divided  by  an  arbitrarily  assumed 
number,  has  that  assumed  number  taken  from  the  quotient :  the  square  of 
half  the  remainder,  with  the  subtractive  number  added  to  it,  is  the  quantity 
(^sought]. ^ 

85.  Question  Z^.  Making  the  residue  of  seconds  of  the  sun  on  Wed- 
nesday, with  ninety-three  added,  or  with  sixty-seven  subtiacted,  an  exact 
square,  [a  proficient  solving  this  problem]  within  a  year  [is]  a  mathemati- 
cian. 

Here  the  subtractive  number  is  QT!  ;  the  additive  number,  93  :  their  sum, 
160:  divided  by  an  assumed  number  4,  makes  40:  less  the  assumed  number, 
leaves  36;  the  half  of  which  is  18  :  its  square,  324  :  added  to  the  subtractive 
quantity  67,  the  quantity  is  found  391-  It  is  the  residue  of  seconds  of  thq 
sun. 

86.  Question  37-  Making  the  residue  of  seconds  of  the  sun  on  Thurs- 
day lessened  and  then  multiplied  by  five,  an  exact  square,  or  by  ten,  [the 
proficient  solving  this  problem]  Avithin  a  year  [is]  a  mathematician. 

'  If  a  pair  of  quantities  equal  or  unequal  be  given  such,  that  a  quantity,  which  lessened  by  the 
iSrst,  is  an  exact  square,  is  also  a  square  when  increased  by  the  second ;  then  the  two  proposed 
quantities  are  to  be  added  together;  and  their  sura  is  to  be  divided  by  some  arbitrary  number. 
From  the  quotient  subtracting  the  same  arbitrary  number,  the  half  of  the  remainder  is  taken :  and 
the  square  of  that  moiety,  added  to  the  number  the  subtraction  of  which  renders  the  quantity  in 
question  a  square,  is  in  every  case  the  quantity  sought.  Com. 

3  B  2 


S72  BRAHMEGUPTA.  Chapter  XVIII. 

This  comprises  two  examples.  In  the  first,  let  residue  of  seconds  be  ^a  1 . 
This  less  five  is  ya  1  rw  5  ;  and  then  multiplied  by  five,  ya  5  ru  25.  It  is  a 
square.  Put  it  equal  to  the  square  of  the  arbitrary  number  ten ;  and  from 
this  equation  a  value  oi y&vat-tdvat  is  obtained,  25.  Or  by  equating  it  with 
the  square  of  five,  the  value  oi ydvat-tavat  comes  out  10.  This  is  a  residue 
of  seconds  of  the  sun. 

In  the  second  example,  the  value  of  residue  of  seconds  is  put  yavat-tdvat, 
ya  1.  This  less  ten,  and  multiplied  by  ten,  becomes  ^a  10  I'u  100.  It  is  a 
square.  Put  it  equal  to  the  square  of  ten  arbitrarily  assumed.  By  this 
equation  the  value  oiydvat-tdvat  is  brought  out  20.  It  is  residue  of  seconds 
of  the  sun. 

By  virtue  of  suppositions  the  answers  are  manifold. 

87.  Question  38.  Making  the  residue  of  revolutions  or  the  like  of  a 
given  object,  lessened  by  ninety-two,  and  multiplied  by  eightj'^-three,  and 
with  unity  added,  an  exact  square,  [the  proficient  solving  this  problem] 
within  a  year  [is]  a  mathematician. 

Since  the  residues  of  revolutions  or  the  like  are  many,  fwtydvat-tdvat  for 
the  value  of  such  residue  ;  ya  \.  This  less  92  1%  ya  1  ru  92.  Multiplied  by 
eighty-three,  it  \sya  83  ru  7636.  With  one  added,  it  becomes  ya  83  ru  7635. 
It  is  a  square.  Put  it  equal  to  the  square  of  unity  as  aia  assumed  number. 
By  this  equation  the  value  of  ydvat  tdvat  comes  out  92-  Thus  the  residue 
of  revolutions  of  some  planet  is  found. 

This  also,  by  means  of  suppositions,  admits  manifold  solutions. 


(     373     ) 


SECTION  vm. 


I 


PROBLEMS. 

88.  Question  39.  From  residue  of  seconds  of  the  moon,  finding  resi- 
due of  minutes  of  the  sun,  or  residue  of  degrees,  or  the  mean  place  of  the 
proposed  planet,  [a  proficient  solving  this  problem]  within  a  year  [is]  a  ma- 
thematician. 

89-  Question  40.  From  residue  of  seconds  of  Jupiter,  find  Mars;  or 
from  residue  of  minutes  of  the  moon,  the  sun ;  or  from  residue  of  revolutions 
of  the  moon;  [a  proficient  solving  this  problem]  within  a  year  [is]  a  mathe- 
matician. 

90.  Rule:  §  50.  The  number  of  [elapsed]  days  deduced  from  the  given 
residue  for  the  given  planet,  is  added  to  a  multiple  of  the  divisor  in  days  by 
the  elapsed  [periods]  in  least  terms.  From  that  the  residue  for  another 
planet,  or  its  place,  [may  be  found].^ 

Example :  When  the  residue  of  degrees  of  the  moon  is  equal  to  seven 
thousand  five  hundred  and  twenty,  tell  me  the  mean  [place  of  the]  sun,  if 
thou  be  conversant  with  the  pulverizer. 

Residue  of  degrees  7520.  Abridged  by  the  common  divisor  of  revolutions 
of  the  moon  and  terrestrial  days,  namely  80,  it  is  94.     For  the  residue  of 

'  From  the  residue  of  revolutions  or  the  liice,  as  given,  relative  to  the  proposed  planet,  the  num- 
ber of  [elapsed]  days  is  to  be  found,  as  before.  It  must  be  converted  into  the  number  of  elapsed 
days  of  the  i/uga.  How  ?  The  rule  proceeds  to  answer.  The  number  of  days,  which  comes  out 
by  the  pulverizer,  must  necessarily  be  short  by  the  divisor  in  days :  for  it  is  the  elapsed  portion  of 
the  present  i/iiga  of  the  planet.  Therefore,  whatever  number  of  its  yugas  may  be  past,  by  that  num- 
ber as  the  elapsed  periods  in  least  numbers,  multiply  the  divisor  in  days,  and  add  the  product;  the 
sum  is  the  complete  number  of  elapsed  days  from  the  beginning  of  the  yugas.  From  that  elapsed 
time,  by  the  [periodical]  revolutions  of  the  other  planet  and  terrestrial  days,  find  the  residue  of 
revolutions  and  so  forth.     Or  the  mean  [place  of  the]  given  planet  may  be  deduced.  Com. 


374  BRAHMEGUPTA.  Chapter  XVIII. 

degrees  of  the  moon,  finding  the  constant  pulverizer,  the  multiplier  is  101. 
Whence  the  number  of  [elapsed]  days  41 .  Here  the  number  for  the  elapsed 
periods  of  the  moon  in  least  terms  is  7.  The  days  in  the  divisor  137,  mul- 
tiplied by  that,  are  959  :  which,  added  to  the  number  of  elapsed  days  by  the 
pulverizer,  41,  makes  the  elapsed  [portion  of  the]  yuga  1000.  Hence  the 
residue  of  revolutions  of  the  sun,  8080 ;  from  which  the  sun's  place  is  to  be 
deduced,  as  before. 

It  is  to  be  in  like  manner  understood  in  all  [similar]  examples. 

91,  Rule  to  find  the  time  or  number  of  days,  after  which  the  same  resi- 
dues of  revolutions  or  the  like  of  two  planets,  or  of  more,  which  occur  on  a 
given  day,  will  recur :  §  5 1 . 

The  divisors  in  least  terms  are  inverted.'  The  result  being  added  to  the 
number  of  days,  the  residues  [occur]  again  in  that  [time].  In  the  same  man- 
tier  for  three  or  more  [planets].     Proceed  as  before  for  the  given  days. 

Example:  At  the  foregoing  number  of  days,  41,  the  residues  of  revolu- 
tions of  the  sun  and  moon  come  out  123  and  68.  When  do  the  same  resi- 
dues of  revolutions  occur  again?  To  find  this,  the  divisors  of  sun  and  moon 
in  least  terms  are  taken  IO96,  and  137.  Their  greatest  common  measure  is 
137.  Abridged  by  this,  the  quotients  are  8,  and  1 :  by  which  the  divisors  in 
least  terms  being  multiplied  become  IO96  and  IO96.  With  this,  being  the 
amount  of  the  equal  denominator,  added  to  the  number  of  days  41,  the  sum 
is  1137;  at  which  the  residues  are  again  the  same.  With  this  addition,  the 
number  of  elapsed  days  may  be  many  ways  [augmented].  " 

In  the  same  manner  for  three  or  more.  The  divisor  for  two  planets  is 
1096;  that  for  a  third,  Mars,  is  685.     Their  greatest  common  divisor  137; 

»  Under  the  residues  of  revolutions  relative  to  the  two  planets,  as  deduced  from  the  number  of 
[elapsed]  days  on  the  given  day,  their  respective  divisors  in  least  terms  stand.  Some  common 
measure  of  them  is  to  be  assumed  by  which  they  may  be  reduced  to  the  lowest  terms.  Being  di- 
vided by  that  common  measure,  the  quotients  serve  to  multiply  reciprocally  those  same  divisors  of 
the  planets  in  least  terms.  This  being  done  the  denominators  are  equal.  Then  add  that,  result 
to  the  number  of  [elapsed]  days ;  and  the  same  residues  of  revolutions  or  the  like  are  deduced  from 
the  sura.  It  is  so  for  two  planets;  and  the  method  is  precisely  the  same  for  three  or  more.  Thus 
the  equal  denominator  arising  from  the  divisors  of  three  given  planets  is  considered  as  one  divisor; 
and  the  third  divisor  of  a  planet,  as  the  second.  From  these,  as  before,  an  equal  denominator  is  t« 
be  deduced.    The  same  must  be  understood  in  regard  to  four  or  more.  Com. 


I 


Sbction'  VIII.  PROBLEMS.  ,  375 

with  which  finding  the  quotients  [8  and  5]  and  proceeding  as  before,  the 
result  [5480]  added  to  the  number  of  days,  41,  makes  5521,  when  the  resi-.; 
dues  are  similar. 

It  must  in  like  manner  be  understood  for  four  or  more  planets. 

Other  examples  are  now  propounded. 

92.  Question  41.  From  residue  of  fewer  days,  making  out  the  number 
of  [elapsed]  days,  and  the  mean  or  the  true  [places  of]  sun  and  moon,  and 
the  lunar  day  and  the  planet,  [a  proficient  solving  these  problems]  within  a 
year  is  a  mathematician. 

Here  are  five  questions.  The  solution  of  them  is  delivered  in  four 
couplets. 

93 — 96.  Rule:  §52 — 55.  Residue  ofy^rfer  days  for  a  single  day,  being 
multiplied  by  some  quantity  and  lessened  by  unity  or  by  revolutions  of  sun 
or  of  moon,  is  exhausted  being  divided  by  terrestrial  days;  or  lessened  by 
unity  [and  divided]  by  lunar.     The  rule  is  as  follows:^ 


•  These  problems  are  relative  to  the  planetary  revolutions  as  taught  in  the  author's  own  astro- 
nomical course.  He  has,  therefore,  here  specified  the  constant  pulverizers  adapted  to  thera.  To 
propound  which  this  first  rule  is  delivered.  Its  meaning  then  is  this  : — The  residue  of  fewer  days 
(terrestrial  than  lunar)  for  a  single  day,  abridged  by  its  own  divisor,  being  multiplied  by  some  num- 
ber, and  having  then  unity  subtracted,  is  exactly  divisible  by  terrestrial  days  reduced  to  least  terms 
by  the  divisor  of/ewer  days.  This  rule,  for  finding  a  multiplier  and  divisor  to  deduce  the  number 
of  [elapsed]  days  from  the  residue  of  fewer  days,  is  as  here  follows  in  the  second  and  succeeding 
couplets  (5  53 — 55);  including  the  finding  of  revolutions.  Residue  o(  fercer  days,  as  proposed  in 
the  problem,  and  reduced  to  least  terms,  being  multiplied  by  108455  and  divided  by  3506481,  the 
remainder  of  the  division  is  the  number  of  [elapsed]  days.  From  that  number,  the  mean  places  of 
sun  and  moon  are  to  be  found :  and  then  to  be  converted  into  the  apparent  planets :  whence  the 
lunar  days;  and  from  these  the  planet  sought  is  to  be  deduced.  Thus  the  solution  of  all  the  pro- 
blems is  effected.  Nevertheless  [a  direct  method  of]  finding  the  residue  of  the  sun's  revolutions  is 
taught  by  the  third  couplet  (^  54).  The  proposed  residue  of  fewer  days  in  least  terms,  being  multi- 
plied by  3249624  and  divided  by  3506481,  the  remainder  of  the  division  is  residue  of  sun's  revolu- 
tions: whence  the  sun,  as  before.  In  like  manner  the  finding  of  the  number  of  [elapsed]  days  being 
effected,  the  deducing  of  lunar  days  was  also  accomplished  :  the  author  shows  how  to  find  the  same 
by  another  [and  direct]  method,  in  the  fourth  couplet  (§  56).  The  residue  of  fewer  days  for  the 
given  time  being  in  least  terms,  and  multiplied  by  1 10179  and  divided  by  3562220,  the  remainder 
of  the  division  is  lunar  days :  under  which  is  the  fraction  of  such  days.  For  the  hours,  minutes, 
&c.  under  days,  which  are  quotient  of  residue  of  fewer  days  divided  by  terrestrial  days,  according 


576  BRAHMEGUPTA.  Chapter  XVIII. 

The  [proposed]  residue  of  fewer  days  [in  least  terms]  being  multiplied  by 
a  hundred  and  eight  thousand,  four  hundred  and  fifty-five,  and  divided  by 
three  millions,  five  hundred  and  six  thousand,  four  hundred  and  eighty-one, 
the  remainder  is  the  number  of  elapsed  days. 

The  proposed  residue  of  fewer  days  [in  least  terms]  being  multiplied 
by  three  millions,  two  hundred  and  forty-nine  thousand,  six  hundred  and 
twenty-four,  and  divided  by  three  millions,  five  hundred  and  six  tliousand, 
four  hundred  and  eighty-one,  the  remainder  which  results  is  the  residue  of 
solar  revolutions. 

The  [proposed]  residue  of  fewer  days  in  least  terms]  being  multiplied  by 
one  hundred  and  ten  thousand,  one  hundred  and  seventy-nine,  and  divided 
by  three  millions,  five  hundred  and  sixty-two  thousand,  two  hundred  and 
twenty,  the  remainder  is  the  lunar  days. 

'97-  Question  42.'  Knowing  the  sum  of  the  residues  of  both  degrees  and 
minutes,  and  their  difference,  say  what  are  the  residues  ? 

Rule :  §  56}  The  sum  set  down  twice  and  having  the  difference  added 
and  subtracted  and  being  in  both  instances  halved,  the  moieties  are  the 
residues. 

98.  Rule:  §  57.  If  the  difference  of  their  squares  and  their  [simple]  diflFer- 
ence  be  given  :  the  difference  of  the  squares  being  divided  by  the  [simple] 
difference  and  having  the  same  added  and  subtracted  and  being  divided  by 

to  the  rule  delivered  in  the  chapter  on  the  solution  of  problems  respecting  mean  motions,*  are  the 
fractional  part  of  lunar  days. 

As  in  finding  the  number  of  [elapsed]  days  from  residue  oi  fewer  days,  the  residue  of  fewer 
days  for  a  single  day  was  put  for  dividend,  unity  for  the  subtractive  quantity,  and  terrestrial  days 
for  divisor;  so,  in  finding  residue  of  solar  revolutions,  the  revolutions  of  the  sun  are  the  subtractive 
quantity;  and,  in  finding  residue  of  lunar  revolutions,  the  revolutions  of  the  moon  are  the  sub- 
tractive  quantity;  and,  in  finding  lunar  days,  unity  is  so  :  but  fiere  days  of  the  moon  are  the  divisor. 
Such  is  the  diflference.  The  author  has  specified  the  constant  pulverizers.  In  like  manner,  when 
a  proposed  planet  is  sought  in  any  example  from  residue  oi  fewer  days,  the  subtractive  quantity  is 
to  be  put  equal  to  the  revolution  of  such  planet,  and  the  constant  pulverizer  is  to  be  thence  brought 
OBt.  *  Com. 

'  Example  of  the  rule  of  concurrence. — Com.     See  §  25. 

*  Second  half  of  the  couplet.     Its  first  half  proposes  a  problem, 

•  Cli.  13.  §  22. 


Section  VIII.  PROBLEMS.  377 

two,  the  quotients  are  the  residues;  whence  the  number  of  elapsed  days  [may 
be  found]. 

99.  Rule:  ^58.  From  twice  the  sum  of  the  squares  subtract  the  square  of 
the  [simple]  sum  of  the  residues.  The  sum  of  residues,  having  the  square- 
root  of  the  remainder  added  and  subtracted,  and  being  divided  by  two,  yields 
the  residues  severally. 

For  instance,  the  sum  of  the  squares  of  the  residues  is  9365  ;  and  the  sum 
of  those  residues  is  117.  The  sum  of  the  squares  doubled  is  18730;  from 
which  subtracting  13689  the  square  of  1 17,  the  remainder  is  5041  ;  of  which 
the  square-root  is  7I-  This  being  added  to  and  subtracted  from  the  sum  of 
residues  and  then  halved,  the  residues  are  found  94  and  23. 

100.  Rule  :  §  59.  From  the  square  of  the  difference  of  residues  added  to 
four  times  the  product  of  residues,  extract  the  square-root,  which  added 
to,  and  subtracted  from,  the  difference  of  residues,  and  halved,  yields  the  re- 
sidues s^erally. 

Example:  Product  of  residues,  2162,  multiplied  by  (4)  square  of  two, 
8648,  added  to  square  (5041)  of  the  difference  of  residues  71,  makes  13689  : 
of  which  the  root  is  117.  This,  having  the  difference  of  residues  added  and 
subtracted,  becomes  188  and  46;  which  halved  are  94  and  23  :  and  the  re- 
sidues are  found. 

101.  These  questions  are  stated  merely  for  gratification.  The  proficient 
may  devise  a  thousand  others;  or  may  resolve,  by  the  rules  taught,  problems 
proposed  by  others. 

102.  As  the  sun  obscures  the  stars,  so  does  the  proficient  eclipse  the 
glory  of  other  astronomers  in  an  assembly  of  people,  by  the  recital  of  alge- 
braic problems,  and  still  more  by  their  solution. 

103.  These  questions  recited  under  each  rule,  with  the  rules  and  their 
examples,  amount  to  an  hundred  and  three  couplets  :  and  this  Chapter  on 
the  Pulverizer  is  the  eighteenth. 

3  c 


378  BRAHMEGUPTA.  Chapter  XVIII. 

Rules,  (sutra,)  sixty-one  and  a  half  couplets :  problems,  (prasna,)  forty- 
one  and  a  half. 

Interpretation  of  the  Algebraic  Pulverizer  in  the  Brahma-sidcThdnta  com- 
posed by  Brahmegupta. 


FINIS.  ^ 


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